е ефеде ецедефе ебедедеф едед-еде ец е ефеде, ебецедефегец е ееецедефедец еее едееецецефец ец е ееецедеф-е ецефедец е ец
|
|
|
- Gabriella McDaniel
- 7 years ago
- Views:
Transcription
1 едецеце, 2009, 9, е ефеде ецедефе ебедедеф едед-еде ец е ефеде, ебецедефегец е ееецедефедец еее едееецецефец ец е ееецедеф-е ецефедец е ец 2009 ее ее, Ав, ед е Ав apple 100-fl Ав, 159; ее appleав ее apple (300, 400Ас) apple (250400Ас) apple е = 1 apple Ав apple Авfl appleав appleapple apple fl Ав apple- Авapple apple Ав ед apple appleав-, appleав apple apple Ав еф-е Ав appleapple Ав appleав fl А 001 mhcl, - fl fl Ав 01 mhcl ег fl appleapple appleав appleapple, fl apple apple Ав Ав apple Ав ееfl- Ав apple fl apple, appleapple appleapple appleавfl appleавfl flfl apple, apple, Авapplefl apple Ав apple едав fl apple apple apple: Авfl Ав apple Ав 0004 / (apple 300Ас), Авapple apple 006 / (apple 400Ас) fl apple Ав 029 / appleав - appleав appleав -- appleapple apple appleappleав, apple apple Ав appleав - apple apple, appleapplefl Ав- appleapple Ав appleав fl Авapple Авapple appleapple : - apple -appleapplefl appleав ееappleapple, е«ав ег, ефappleав- еф, ее Ав Авapple fl flfl Ав apple-, flfl - Ав fl appleapple apple Авappleapple appleapple, Авappleapple- Ав apple Ав-Авapple- apple ец, appleapple, apple apple- apple appleав appleав - appleapplefl Ав appleapple-appleав, appleapplefl Ав [1] - appleав, Авfl Авappleapple appleapple, apple-, apple Ав appleав - apple [2, 3] apple apple- Авfl appleав Авapple- appleapple apple fl Ав apple - appleapple apple apple apple Авapplefl apple NaCaFeAlSiClSH 2 OO 2 ег Ав appleapple NaCl KCl apple Ас е = 1 apple - apple [4, 5], Ав-- Авapple, Авfl Ав appleав appleapple apple (186 < ph < 86), АвАвapple appleав (54 < ph < 66) apple - Ав apple Ав-Авapple apple Ав,,, Ав- apple, apple, appleapple, apple, - - appleав Авappleapple appleapple ец Авfl appleapple, Ав fl, - fl appleapple fl, apple appleapple 350Ас ph appleав 65 - applefl Авapple: Ca 2 Al 2 FeSi 3 O 12 (OH) (Ep 33 ) Fe 2 O 3 (Hem) + 7SiO 2 (Qtz) + 2Na H 2 O = = 2CaFeSi 2 O 6 (Hd) + 2NaAlSi 3 O 8 (Ab) + 2H O 2 е applefl fl appleавfl appleappleapple apple Ав-Авapple- apple, appleав appleав [6] ефец ец ефедец е apple -- Ав apple Ас Ав Ав 1 apple е apple apple (1 mnacl, 1 mnacl mhcl, 988
2 е ефеде ецедефе ебедедеф едед-еде ец е ефеде 989 еф 1 fl applefl Au apple appleapple, appleapple Ав - fl EpQtzAbCcHem А Mgt (1) EpQtzAbCcHem-Py А Mgt (2) apple е = 1 apple е apple 1 2 ееappleapple apple* lgmau N** ph lgmau N 300АсC 1 m NaCl m HCl m NaCl m NaCl m NaOH АсC 1 m NaCl m HCl m NaCl m NaCl m NaOH 70*** * ецapple А 02 Ав, ** е«, *** ееfl appleав Авapple 1 mnacl mnaoh) Ав - (9 А 02 А 80 ) apple ( ) appleав Ав appleapple, apple apple Ав ец- apple appleapple, Авfl apple, Ав Ав Ав- fl appleapple fl applefl appleавfl apple apple Ав apple ( Ав-Авapple- apple) appleав Ав f O2 АвАвapple- - () apple, f S2 apple-- (е ) apple-appleapple- (е е ) Ав apple fl (): Ав-50, -20, apple-30, -10; Ав-Авapple apple: Ав-30, Авapple-30, -15, apple-30 е Авfl apple fl (): (); apple-50, (е ); appleapple-40, apple (е е ) appleав - appleав appleapple apple- apple е ед-3 appleapple- Ав appleapple fl 335 apple, appleflfl apple-, (): 2130 apple Ас fl applefl appleapple appleавfl Ав appleавapple apple Ав- Ав ец Ав apple appleapple (- appleapple -6200) Ав- fl appleapple А ее- 110А apple ец ед е е ебеге ефеф едееефед Ав Ав apple apple- apple NaCl apple- АвappleАв apple е appleавfl apple Ав- apple fl, apple - Ав appleapple appleapple appleав apple, f Na + O2, : Ep Qtz + Hem + 2CO H 2 O + 2Na + = (1) = 2Ab + Mgt + 2Cc + 025O 2 + 2H +, apple apple: Ep Qtz + 2Mgt + 2CO 2 + 2S H 2 O+ + 2Na + = 2Ab + 25Hem + 2Py + 2Cc + O 2 + 2H + (2) Ав fl, appleapple, apple (1) apple 300Ас, Ав Ав 56 < apple < 66 ( 1) ееapple Ав appleapple АвАвapple apple -, appleapple apple appleapple appleflав ег appleapple apple apple- Ав (1) - Авapple appleав apple 400Ас apple- appleapple, АвappleАв apple- apple [4] е appleapple flflfl, apple, appleав Авfl -
3 990 ее Авapple Ep 33 + Qtz + Hem + Ab + Mgt + Cc (1) Ep 33 + Qtz + Mgt + Ab + Hem + Py + Cc (2) Ав appleapple NaCl apple apple 250, 300, Ас (е = 1 apple) appleflав appleapple appleapple appleав appleapple 1mNaCl 3 ец apple Ав appleapple apple Авfl fl (1) (2) apple 2 едав, - apple appleapplefl fl appleав (fl ) apple apple - (1) Авfl appleapple () appleав - fl Авfl apple е () е - Ав, apple, Ав- apple fl apple Ав fl fl Авapple apple - Ав Ав appleеф 2 fl applefl ( lgmau) appleapple (е = 1 apple) ецав appleapple applefl fl I II III 300АсC 1 m NaCl m HCl * m NaCl * m NaCl m NaOH * 400АсC 1 m NaCl m HCl m NaCl m NaCl m NaOH I EpHdAbQtzHemMgt; II EpHdAbQtzHemPyMgt; III EpHdAbQtzPyPoMgt; * ееfl appleав fl Ав apple apple appleapple apple Ав Ав-Авapple apple appleapple NaCl е, apple - : Ep 33 + Hd + Ab + Cc + Qtz + Hem + Mgt (I), Ep 33 + Hd + Ab + c + Qtz + Hem + Py + Mgt (II) Ep + Hd + Ab + Qtz + Py + Po + Mgt (III) Ав 2 ебав, appleавав applefl -, fl appleapple АвappleАв appleapple ед, Авapple apple 300АсC fl : CaFeSi 2 O FeS 2 + 2H 2 O O 2 CaSO 4 А 2H 2 O + 075Fe 2 O 3 + 2SiO 2 Авapple appleав d/n 756; 423; applefl, Ав, apple- Ав, lgmau дм, е 1 fl applefl fl apple ( lgmau) appleapple 1 m NaCl m NaOH apple 300Ас/1 apple apple 30 - fl Авapple CaSO 4 ееав Ав- apple d/n 387; 350; 285; 232; fl applefl appleapplefl apple- apple е apple 300Ас appleapplefl - apple, Ав apple- apple (apple 1) apple apple apple apple - Авapple Авapple е fl-,, flfl apple apple appleapple apple- III ( 2), applefl, Ав appleав - appleapple fl flfl appleав- - apple apple Авapple applefl CaFeAlSiH 2 OClSO 2 apple apple Ep + Hd + Ab + Cc + Qtz + Po + Py + Mgt ед, fl, Авapple flflfl, appleав Ав [7] е е«ефед едеце едец ееfl applefl appleapple Ав, appleав, Ав- apple Ав - apple apple- apple А apple-а [8] Ав fl appleapple 1mNaCl, 1mNaCl + 01mHCl, 1mNaCl + 01mNaOH appleapple appleав applefl apple- apple apple - fl 3 30 ец applefl appleав Ав SUPCRT98 Авapple- apple apple [9],, Авfl АвappleАв -
4 е ефеде ецедефе ебедедеф едед-еде ец е ефеде 991 еф 3 apple appleapple appleapple 1 m NaCl apple EpQtzAbCcHemMgt (1) EpQtzAbCcHemPyMgt (2) (е = 1 apple) ееappleapple 1 2 t, АсC ph lg f O lg f S lgm д Au apple (+01mHCl) apple appleав, - appleав, appleавfl appleapple Ав, apple 350Ас -, applefl,, appleав apple- (1) appleав АвАвapplefl - (1) 45 Ав fl appleapple- apple Ав еф-е Авfl apple ( 3), flfl - appleapple apple (2) apple- Ав- appleав Авfl -, АвappleАвfl apple, applefl ееfl apple - appleав, appleав, apple- apple appleflав, fl-, apple, fl Авapple- Ав applefl АвАв - appleapple apple- apple apple appleав- apple (2) appleав 4 -, applefl apple apple Ав apple А apple - А (mau > ) apple apple appleав fl Au +, applefl apple- А appleа Ep 33 + Hd + Ab + Cc + Qtz + Hem А Mgt (I) Ep 33 + Hd + Ab + Cc + Qtz + Hem + Py + Mgt (II) е appleapple appleав, apple appleapple, apple appleавав-, apple fl - apple 300, 350, 400, Ас apple е = 1 apple applefl (I) apple Ав- appleapple Ав 001 mhcl - е fl АвАвapple appleав, apple apple Ав Ас appleав 5 ееfl apple - (II) appleapplefl Ав appleapple ( 01 mhcl) appleapplefl appleав - fl ( 6) ефappleав appleapple, Ав fl (I), (II) apple е, appleав еф-apple apple 3 ебав Ав, fl -apple-- Авfl - fl apple, appleавflfl -, appleав- appleав appleapple- fl, apple - Авapple fl Авapple (Anh), apple apple 300, 400Ас apple е = = 1 apple apple Авfl appleapple NaCl Ep 33 + Ab + Anh + Qtz + Hem + Py + Mgt ( 7) ееавappleав apple, applefl АвАвapple apple- appleав (apple = 585 apple 300Ас) appleавfl - appleapple ( lgmau = 715) е apple apple - apple ( 2) ееав - fl Авapple Авapple Авapple Авfl applefl apple - Anh Ав Hd ед, apple- ph * * t, АсC е 2 е appleав appleapple apple- Ав applet, АсC (е = 1 apple) ецав appleapple: 1 1 m NaCl m HCl; 2 1 m NaCl m HCl; 3 1 m NaCl; 4 1 m NaCl m NaOH; appleapple, appleapple fl: EpQtzAbCcHemMgt, EpQtzAbCcHemе ymgt HemPyMgt * *
5 992 ее Авapple еф 4 еб appleав, appleapple EpQtzAbCcHemMgtPy (е = 1 apple) АсC lgm i Au AuCl AuC l Au(HS AuHS ) 2 apple Hd appleав apple Ав -, apple, appleapple - appleав (638 < ph < 654), Ав appleapple apple едегец е ебеге ефефед apple appleapple, apple Ав, apple apple apple- Ав appleав Ав apple apple fl 23 appleflав apple е fl, apple,, applefl Ав Авfl АвappleАв, Ав apple appleapple Ав [10, 11] fl - Ав appleapple- fl apple Ав apple 300, 400Ас е = 1 apple, appleapple А А [12] Ав appleав - UNITHERM, АвappleАв - ед, apple- apple apple apple 05 appleflав еф, appleapple, apple apple apple- apple apple 300АсC lgmau aq = 745 ееapple apple apple appleавapple- А appleа, fl appleapple fl apple- apple apple appleapple 2 appleflав е fl fl-, apple, Ав - apple АвappleАв AuHS 0, - apple Ав apple appleавfl appleflав appleapple ( 4 6) applefl apple Anh apple- ( 7), appleавfl- appleapple, fl Au(HS ) 2 applefl, applefl appleapple fl ( lgmau = , - ) ецfl Авfl, appleapple apple - 0 apple < 55 Авapple HAu(HS ) 2 [13, 7] едав Ав, fl applefl - appleapple appleapple appleавflfl Ав apple Ав Ав, Ав appleapple- Ав- Ав apple АвappleАв - appleapple ец fl fl - appleapple Ав fl [14] applefl apple Авapple - fl А in situа Ав appleapple - appleав- еф 5 fl applefl apple appleapple, Ав EpHdAb CcQtzHem А Mgt (е = 1 apple) е apple АсC ph 1 m NaCl m NaOH m NaCl m NaCl m HCl m NaCl m HCl m NaCl + 01 m HCl lgm Au aq 1 m NaCl m NaOH m NaCl m NaCl m HCl m NaCl m HCl m NaCl + 01 m HCl
6 е ефеде ецедефе ебедедеф едед-еде ец е ефеде 993 еф 6 fl applefl apple appleapple, Ав EpHdAb CcQtzHemPyMgt (е = 1 apple) е apple АсC apple 1 m NaCl + 01 m NaOH m NaCl m NaCl m HCl m NaCl m HCl m NaCl + 01 m HCl lgm Au aq 1 m NaCl + 01 m NaOH m NaCl m NaCl m HCl m NaCl m HCl m NaCl + 01 m HCl appleав, appleapplefl Авfl appleав appleapple apple apple fl еф fl appleав apple, apple АвАв appleapple еф apple, apple - apple, Авfl Авapple Авapple, - fl applefl apple apple fl appleapple appleflав - appleав, appleapple appleав- - fl еф, appleapple, apple Ас appleapple Cu, Zn Pb appleав appleapple, appleapple fl- --apple (FspMsQtz) - - [1] е apple fl- appleав apple appleав (PPM PHM) (FspMsQtz) apple [15] apple Ав apple, fl FspMsQtz appleавfl apple appleав, Ав PP PHM appleав- Ав apple, - Ав (е е, е ) АвАвapple, appleав Ав 33 < apple < 37 е -еф fl [16] е apple- apple fl, - appleавfl apple fl appleав, fl ееapple fl- fl appleав appleapple, apple, fl appleавfl Ав apple- appleав еф-apple apple - Ав (apple 2) apple apple appleав apple apple appleapple (), Ав apple apple () ееapple Ав apple Ав-Авapple apple Ав, - apple appleав appleapple apple, Ав apple - apple, Ав ееfl apple fl apple apple appleapple (apple 2), - appleав appleавfl, apple, apple HemPyMgt е fl appleapple, Ав apple fl apple apple apple - ( 1 2) е apple fl ( /): ph t, АсC е 3 е fl Авapple applet, АсC appleав appleapple, appleapple apple apple - fl (е = 1 apple) 1 EpHdAbQtzHemMgt; 2 EpHdAbQtzHemMgtPy; 3 HemPyMgt 7
7 994 ее Авapple еф 7 appleав, apple applefl appleapple, appleapple AbEpAnhQtzHemPy А Mgt (е = 1 apple) е apple lg f O2 300Ас 400Ас ph lgmau lg ph lgmau f O2 1 m NaCl m NaOH m NaCl m NaCl m HCl m NaCl + 01 m HCl* m NaCl m HCl** m NaCl m HCl** m NaCl m NaOH** m NaCl m NaOH** m NaCl + 01 m NaOH** Ав Ав Авapple applefl * applefl** appleав Ав apple apple 0004 (apple 300Ас/1 apple), fl Ав-- Авapple apple Ав 006 (apple 400Ас/1 apple) Ав 029 fl apple ед Ав appleав appleавfl, apple, appleapple, apple Авappleapple appleapple - fl Авflfl - Авfl, fl Авapple Ав- apple apple, apple- apple АвАвfl fl appleappleapplefl Авappleapple- appleapple apple Ав - Ав, Ав appleapple apple Ав- Ав apple - ед е -еф / apple Авappleapple apple- Ав appleapple apple, apple apple Ав Ав - apple appleapple apple - Ав Ав, apple- fl 170Ас [17, 18] apple apple fl appleapple-, appleав - Авapple Ав Ав [19] едав- Ав АвappleАв - apple [20, 7, 14], fl appleapple appleав, АвАвapple apple fl, - apple apple, apple appleав - apple Ав ееfl apple appleав appleapple apple appleapple apple appleавfl apple apple- apple (Ав 145 ppm apple 500Ас) [17] ее apple, Ав Авappleapple appleapple flfl, apple-, FeCl + ( АвappleАв apple) Au(HS) 2 Авapple - apple 300Ас appleавfl apple apple - appleapple ( 2) apple apple appleав Авapple, Ав applefl, apple- едав, applefl fl appleflав - apple appleapplefl fl apple apple (apple 1) Ав- fl apple fl apple, -, appleapple Ав apple [21, 22] apple MnO Ав Mn 3 O 4 apple АвappleАв apple appleapple apple Ав fl Ав apple ееав apple - apple - - appleapple appleав, appleав, Ав apple appleapple apple apple Авappleapple [23] ец, apple Авapple flfl- fl apple,, appleав, - applefl appleapple appleав ебе«ец ег fl appleapple- appleав appleapple apple - Ав Ав apple, Авapple- Ав, flflfl - apple appleав appleapple ее, apple apple Ав Ас (1 apple) -
8 е ефеде ецедефе ебедедеф едед-еде ец е ефеде 995 Ав appleapple, apple mhcl Ав apple apple Ав- apple appleapple - apple apple apple Ав, apple, fl apple apple appleав apple-- Ав apple appleав, Авappleapple apple- apple,, apple - appleав-, - appleав Ав АвappleАв едав Авappleapple appleapple appleав Ав apple - apple fl appleapple appleав (appleapple, appleapple ) ег- apple apple Ав-appleАв appleав apple appleapple - apple fl Ав apple Ав-Авapple apple Ав ец - appleapple - apple apple appleав fl Ав apple apple- fl apple apple appleав ееецед ецефе ефеге 1 Hemley JJ, Hunt JP Hydrothermal ore-forming processes in the light of studies in rock-buffered systems // Econ Geol 1992 V 87 P apple ед apple applefl // е Ав- apple ецав е е apple ее ее е apple Ав Ав appleав-apple appleapple // fl ее ее, apple еце е apple- Ав Ав- appleав appleapple // е 1991 еф ее ее, Ав,, fl- ецец - fl appleapple- fl apple appleавfl apple // ефfl 2004 еф Hayashi KJ, Ohmoto H Solubility of gold in NaCl and H 2 S-bearing aqueous solutions at АсC // Geochim Cosmochim Acta 1989 V 53 P apple ец, е«ав,, -, ее, ефapplefl, fl Ав apple apple apple apple apple // fl 1995 еф Johnson JW, Oelkers EH, Helgeson HC A software package for calculations of the standard molal thermodynamic properties of minerals, gases, aqueous species, and reactions from 1 to 5000 bars and 0 to 1000АсC // Computer Geosciences 1992 V 77 P еб, apple, apple еф ег Авapple AuOHАс Ав apple Ас Ав // fl , еб ефappleав appleав, АвappleАв Авapple- Ag(1), Cu(1) Au(1) Ав apple- apple 25500Ас Ав <2000 apple // fl 2001 N Shvarov YuV Algorithmization of the numeric equilibrium modeling of dynamic geochemical processes // Geochem Intern 1999 V 37 N 6 P Shenberger DH, Barnes HL Solubility of gold in aqueous sulfide solutions from 150 to 350АсC // Geochim Cosmochim Acta 1989V 53 P Ав, apple еце е apple Ав Ав-appleАв appleав apple Ас е = 1 apple // fl Gibert F, Pascal ML and Pichavant M Gold solubility and speciation in hydrothermal solutions: experimental study of the stability of hydrosulfide complex of gold (AuHSАс) at 350 to 450АсC and 500 bars // Geochim Cosmochim Acta 1998 V 62 P Crerar DA, Susak NJ, Boresik M, and Schwartz S Solubility of the buffer assemblage pyrite-pyrrhotite-magnetite in NaCl solutions from 200 to 350АсC // Geochim Cosmochim Acta 1978 V 42 P Rytuba J Geochemistry of hydrothermal transport and deposition of gold and sulfide minerals in Carlin-type gold deposits // US GS Bull 1985 Sp pap B164 P apple еце fl, applefl - appleав appleав 1991 : 301 c 19 Wood SA, Crerar DA and Borcsik MP Solubility of the assemblage pyrite-pyrrhotite-magnetite-sphalerite-galenagold in H 2 O-NaCl-CO 2 solutions from 200 to 350АсC // Econ Geol 1987 V 82 P Seward TM The transport and deposition of gold in hydrothermal systems // In Gold 82: The geology, Geochemistry and Genesis of Gold Deposits (ed RP Foster) 1984 P Likhoidov GG, Plyusnina LP, Scheka JA, and AphanasА»eva TB Experimental study of gold and platinum solubility in a complex fluid under hydrothermal conditions // Resource Geology 2000 V 50 No2 P ее ее fl appleав - MnO 2 H 2 O appleapple - apple Ас 1 apple // fl ее ее apple apple едав applefl // ед е 2007 N *
е ефе едееедебед ец ец ецеееде ебедец ецедефеце«ец ецедеце
едеге е е ецедедеце, 2009, 43, 5, 795806 ег 57721 LTR-appleappleapple - apple applefl apple, apple- appleapple е appleapple apple - LINE (long interspersed elements) е 3 7 apple apple LINE apple apple
Summer 2003 CHEMISTRY 115 EXAM 3(A)
Summer 2003 CHEMISTRY 115 EXAM 3(A) 1. In which of the following solutions would you expect AgCl to have the lowest solubility? A. 0.02 M BaCl 2 B. pure water C. 0.02 M NaCl D. 0.02 M KCl 2. Calculate
2. Write the chemical formula(s) of the product(s) and balance the following spontaneous reactions.
1. Using the Activity Series on the Useful Information pages of the exam write the chemical formula(s) of the product(s) and balance the following reactions. Identify all products phases as either (g)as,
2. DECOMPOSITION REACTION ( A couple have a heated argument and break up )
TYPES OF CHEMICAL REACTIONS Most reactions can be classified into one of five categories by examining the types of reactants and products involved in the reaction. Knowing the types of reactions can help
CHAPTER 21 ELECTROCHEMISTRY
Chapter 21: Electrochemistry Page 1 CHAPTER 21 ELECTROCHEMISTRY 21-1. Consider an electrochemical cell formed from a Cu(s) electrode submerged in an aqueous Cu(NO 3 ) 2 solution and a Cd(s) electrode submerged
4. Using the data from Handout 5, what is the standard enthalpy of formation of BaO (s)? What does this mean?
HOMEWORK 3A 1. In each of the following pairs, tell which has the higher entropy. (a) One mole of liquid water or one mole of water vapor (b) One mole of dry ice or one mole of carbon dioxide at 1 atm
CHEMISTRY 101 EXAM 3 (FORM B) DR. SIMON NORTH
1. Is H 3 O + polar or non-polar? (1 point) a) Polar b) Non-polar CHEMISTRY 101 EXAM 3 (FORM B) DR. SIMON NORTH 2. The bond strength is considerably greater in HF than in the other three hydrogen halides
Steps for balancing a chemical equation
The Chemical Equation: A Chemical Recipe Dr. Gergens - SD Mesa College A. Learn the meaning of these arrows. B. The chemical equation is the shorthand notation for a chemical reaction. A chemical equation
Hydrothermal Solutions and Ore Deposits
Hydrothermal Solutions and Ore Deposits Physical Chemistry of Minerals and Aqueous Solutions D.M. Sherman, University of Bristol Chalcophiles, Lithophiles, Siderophiles.. Lithophile = oxides, silicates
Balancing Reaction Equations Oxidation State Reduction-oxidation Reactions
Balancing Reaction Equations Oxidation State Reduction-oxidation Reactions OCN 623 Chemical Oceanography Balanced chemical reactions are the math of chemistry They show the relationship between the reactants
NET IONIC EQUATIONS. A balanced chemical equation can describe all chemical reactions, an example of such an equation is:
NET IONIC EQUATIONS A balanced chemical equation can describe all chemical reactions, an example of such an equation is: NaCl + AgNO 3 AgCl + NaNO 3 In this case, the simple formulas of the various reactants
Common Ion Effects. CH 3 CO 2 (aq) + Na + (aq)
Common Ion Effects If two reactions both involve the same ion, then one reaction can effect the equilibrium position of the other reaction. The ion that appears in both reactions is the common ion. Buffers
CHM1 Review for Exam 12
Topics Solutions 1. Arrhenius Acids and bases a. An acid increases the H + concentration in b. A base increases the OH - concentration in 2. Strong acids and bases completely dissociate 3. Weak acids and
K + Cl - Metal M. Zinc 1.0 M M(NO
Redox and Electrochemistry This section should be fresh in your minds because we just did this section in the text. Closely related to electrochemistry is redox chemistry. Count on at least one question
Redox and Electrochemistry
Name: Thursday, May 08, 2008 Redox and Electrochemistry 1. A diagram of a chemical cell and an equation are shown below. When the switch is closed, electrons will flow from 1. the Pb(s) to the Cu(s) 2+
Chapter 3 Mass Relationships in Chemical Reactions
Chapter 3 Mass Relationships in Chemical Reactions Student: 1. An atom of bromine has a mass about four times greater than that of an atom of neon. Which choice makes the correct comparison of the relative
Chapter 8: Chemical Equations and Reactions
Chapter 8: Chemical Equations and Reactions I. Describing Chemical Reactions A. A chemical reaction is the process by which one or more substances are changed into one or more different substances. A chemical
Chemistry: Chemical Equations
Chemistry: Chemical Equations Write a balanced chemical equation for each word equation. Include the phase of each substance in the equation. Classify the reaction as synthesis, decomposition, single replacement,
1332 CHAPTER 18 Sample Questions
1332 CHAPTER 18 Sample Questions Couple E 0 Couple E 0 Br 2 (l) + 2e 2Br (aq) +1.06 V AuCl 4 + 3e Au + 4Cl +1.00 V Ag + + e Ag +0.80 V Hg 2+ 2 + 2e 2 Hg +0.79 V Fe 3+ (aq) + e Fe 2+ (aq) +0.77 V Cu 2+
5.111 Principles of Chemical Science
MIT OpenCourseWare http://ocw.mit.edu 5.111 Principles of Chemical Science Fall 2008 For information about citing these materials or our Terms of Use, visit: http://ocw.mit.edu/terms. Page 1 of 10 pages
Aqueous Solutions. Water is the dissolving medium, or solvent. Some Properties of Water. A Solute. Types of Chemical Reactions.
Aqueous Solutions and Solution Stoichiometry Water is the dissolving medium, or solvent. Some Properties of Water Water is bent or V-shaped. The O-H bonds are covalent. Water is a polar molecule. Hydration
Name period Unit 9: acid/base equilibrium
Name period Unit 9: acid/base equilibrium 1. What is the difference between the Arrhenius and the BronstedLowry definition of an acid? Arrhenious acids give H + in water BronstedLowry acids are proton
Electrochemistry - ANSWERS
Electrochemistry - ANSWERS 1. Using a table of standard electrode potentials, predict if the following reactions will occur spontaneously as written. a) Al 3+ + Ni Ni 2+ + Al Al 3+ + 3e - Al E = -1.68
AP FREE RESPONSE QUESTIONS ACIDS/BASES
AP FREE RESPONSE QUESTIONS ACIDS/BASES 199 D A chemical reaction occurs when 100. milliliters of 0.200molar HCl is added dropwise to 100. milliliters of 0.100molar Na 3 P0 solution. (a) Write the two net
REVIEW QUESTIONS Chapter 8
Chemistry 51 ANSWER KEY REVIEW QUESTIONS Chapter 8 1. Identify each of the diagrams below as strong electrolyte, weak electrolyte or non-electrolyte: (a) Non-electrolyte (no ions present) (b) Weak electrolyte
Experiment 8 - Double Displacement Reactions
Experiment 8 - Double Displacement Reactions A double displacement reaction involves two ionic compounds that are dissolved in water. In a double displacement reaction, it appears as though the ions are
Titrations. Acid-Base Indicators and Titration Curves. Shapes of Titration Curves. A titration curve is a graphical history of a titration
Acid-Base Indicators and Titration Curves Titrations In a titration a solution of accurately known concentration is added gradually added to another solution of unknown concentration until the chemical
stoichiometry = the numerical relationships between chemical amounts in a reaction.
1 REACTIONS AND YIELD ANSWERS stoichiometry = the numerical relationships between chemical amounts in a reaction. 2C 8 H 18 (l) + 25O 2 16CO 2 (g) + 18H 2 O(g) From the equation, 16 moles of CO 2 (a greenhouse
Chemical Equations. Chemical Equations. Chemical reactions describe processes involving chemical change
Chemical Reactions Chemical Equations Chemical reactions describe processes involving chemical change The chemical change involves rearranging matter Converting one or more pure substances into new pure
Name: Class: Date: 2 4 (aq)
Name: Class: Date: Unit 4 Practice Test Multiple Choice Identify the choice that best completes the statement or answers the question. 1) The balanced molecular equation for complete neutralization of
Equilibrium Constants The following equilibrium constants will be useful for some of the problems.
1 CH302 Exam 4 Practice Problems (buffers, titrations, Ksp) Equilibrium Constants The following equilibrium constants will be useful for some of the problems. Substance Constant Substance Constant HCO
Experiment 1 Chemical Reactions and Net Ionic Equations
Experiment 1 Chemical Reactions and Net Ionic Equations I. Objective: To predict the products of some displacement reactions and write net ionic equations. II. Chemical Principles: A. Reaction Types. Chemical
NAMING QUIZ 3 - Part A Name: 1. Zinc (II) Nitrate. 5. Silver (I) carbonate. 6. Aluminum acetate. 8. Iron (III) hydroxide
NAMING QUIZ 3 - Part A Name: Write the formulas for the following compounds: 1. Zinc (II) Nitrate 2. Manganese (IV) sulfide 3. Barium permanganate 4. Sulfuric acid 5. Silver (I) carbonate 6. Aluminum acetate
Chemistry 51 Chapter 8 TYPES OF SOLUTIONS. A solution is a homogeneous mixture of two substances: a solute and a solvent.
TYPES OF SOLUTIONS A solution is a homogeneous mixture of two substances: a solute and a solvent. Solute: substance being dissolved; present in lesser amount. Solvent: substance doing the dissolving; present
Chapter 17. The best buffer choice for ph 7 is NaH 2 PO 4 /Na 2 HPO 4. 19)
Chapter 17 2) a) HCl and CH 3 COOH are both acids. A buffer must have an acid/base conjugate pair. b) NaH 2 PO 4 and Na 2 HPO 4 are an acid/base conjugate pair. They will make an excellent buffer. c) H
General Chemistry II Chapter 20
1 General Chemistry II Chapter 0 Ionic Equilibria: Principle There are many compounds that appear to be insoluble in aqueous solution (nonelectrolytes). That is, when we add a certain compound to water
Moles. Moles. Moles. Moles. Balancing Eqns. Balancing. Balancing Eqns. Symbols Yields or Produces. Like a recipe:
Like a recipe: Balancing Eqns Reactants Products 2H 2 (g) + O 2 (g) 2H 2 O(l) coefficients subscripts Balancing Eqns Balancing Symbols (s) (l) (aq) (g) or Yields or Produces solid liquid (pure liquid)
Moles. Balanced chemical equations Molar ratios Mass Composition Empirical and Molecular Mass Predicting Quantities Equations
Moles Balanced chemical equations Molar ratios Mass Composition Empirical and Molecular Mass Predicting Quantities Equations Micro World atoms & molecules Macro World grams Atomic mass is the mass of an
Aqueous Ions and Reactions
Aqueous Ions and Reactions (ions, acids, and bases) Demo NaCl(aq) + AgNO 3 (aq) AgCl (s) Two clear and colorless solutions turn to a cloudy white when mixed Demo Special Light bulb in water can test for
SEATTLE CENTRAL COMMUNITY COLLEGE DIVISION OF SCIENCE AND MATHEMATICS. Oxidation-Reduction
SEATTLE CENTRAL COMMUNITY COLLEGE DIVISION OF SCIENCE AND MATHEMATICS OxidationReduction Oxidation is loss of electrons. (Oxygen is EN enough to grab e away from most elements, so the term originally meant
= 11.0 g (assuming 100 washers is exact).
CHAPTER 8 1. 100 washers 0.110 g 1 washer 100. g 1 washer 0.110 g = 11.0 g (assuming 100 washers is exact). = 909 washers 2. The empirical formula is CFH from the structure given. The empirical formula
Decomposition. Composition
Decomposition 1. Solid ammonium carbonate is heated. 2. Solid calcium carbonate is heated. 3. Solid calcium sulfite is heated in a vacuum. Composition 1. Barium oxide is added to distilled water. 2. Phosphorus
ph: Measurement and Uses
ph: Measurement and Uses One of the most important properties of aqueous solutions is the concentration of hydrogen ion. The concentration of H + (or H 3 O + ) affects the solubility of inorganic and organic
AP Chemistry 2010 Free-Response Questions Form B
AP Chemistry 010 Free-Response Questions Form B The College Board The College Board is a not-for-profit membership association whose mission is to connect students to college success and opportunity. Founded
OXIDATION REDUCTION. Section I. Cl 2 + 2e. 2. The oxidation number of group II A is always (+) 2.
OXIDATION REDUCTION Section I Example 1: Na Example 2: 2C1 Example 3: K + + e Na + + e Cl 2 + 2e K Example 4: C1 2 + 2e 2Cl 1. The oxidation number of group I A is always (+) 1. 2. The oxidation number
Solubility of Salts - Ksp. Ksp Solubility
Solubility of Salts - Ksp We now focus on another aqueous equilibrium system, slightly soluble salts. These salts have a Solubility Product Constant, K sp. (We saw this in 1B with the sodium tetraborate
10. Calculate the mass percent nitrogen in (NH 4 ) 2 CO 3 (molar mass = 96.09 g/mol). a. 29.1 % c. 17.9 % e. 14.6 % b. 35.9 % d. 0.292 % f. 96.
Chem 171-2-3: Final Exam Review Multiple Choice Problems 1. What is the molar mass of barium perchlorate, Ba(ClO 4 ) 2? a. 189.90 g/mol c. 272.24 g/mol e. 336.20 g/mol b. 240.24 g/mol d. 304.24 g/mol f.
Unit 10A Stoichiometry Notes
Unit 10A Stoichiometry Notes Stoichiometry is a big word for a process that chemist s use to calculate amounts in reactions. It makes use of the coefficient ratio set up by balanced reaction equations
Chapter 6 Notes Science 10 Name:
6.1 Types of Chemical Reactions a) Synthesis (A + B AB) Synthesis reactions are also known as reactions. When this occurs two or more reactants (usually elements) join to form a. A + B AB, where A and
Ch 20 Electrochemistry: the study of the relationships between electricity and chemical reactions.
Ch 20 Electrochemistry: the study of the relationships between electricity and chemical reactions. In electrochemical reactions, electrons are transferred from one species to another. Learning goals and
Complexometric Titrations
Complexometric Titrations Complexometric titrations are based on the formation of a soluble complex upon the reaction of the species titrated with the titrant. M + L ML In the module Chemistry 2 you were
MIXING OF CO 2 AND CH 4 IN GAS RESERVOIRS: CODE COMPARISON STUDIES
MIXING OF CO 2 AND CH 4 IN GAS RESERVOIRS: CODE COMPARISON STUDIES C.M. Oldenburg 1, D.H.-S. Law 2, Y. Le Gallo 3, S.P. White 4 1 Earth Sciences Division 90-1116, Lawrence Berkeley National Laboratory
GEOL 414/514 CARBONATE CHEMISTRY
GEOL 414/514 CARBONATE CHEMISTRY Chapter 6 LANGMUIR SOLUBILITY OF CALCITE CaCO 3 in nature: calcite & aragonite Reaction with strong acid: CaCO 3 + 2H + Ca +2 + H 2 O + CO 2 Reaction with weak acid: CaCO
Chemistry 106 Fall 2007 Exam 3 1. Which one of the following salts will form a neutral solution on dissolving in water?
1. Which one of the following salts will form a neutral solution on dissolving in water? A. NaCN B. NH 4 NO 3 C. NaCl D. KNO 2 E. FeCl 3 2. Which one of the following is a buffer solution? A. 0.10 M KCN
Ion Selective Electrodes
Ion Selective Electrodes OAKTON has a large selection of Ion Selective Electrodes () to suit a wide variety of applications. Each electrode has a typical response time of 20 to 30 seconds but will vary
SAMPLE PROBLEM 8.1. Solutions of Electrolytes and Nonelectrolytes SOLUTION STUDY CHECK
Solutions of Electrolytes and Nonelectrolytes SAMPLE PROBLEM 8.1 Indicate whether solutions of each of the following contain only ions, only molecules, or mostly molecules and a few ions: a. Na 2 SO 4,
Chapter 13. Properties of Solutions
Sample Exercise 13.1 (p. 534) By the process illustrated below, water vapor reacts with excess solid sodium sulfate to form the hydrated form of the salt. The chemical reaction is Na 2 SO 4(s) + 10 H 2
Electrochemistry Voltaic Cells
Electrochemistry Voltaic Cells Many chemical reactions can be classified as oxidation-reduction or redox reactions. In these reactions one species loses electrons or is oxidized while another species gains
Chapter 13: Electrochemistry. Electrochemistry. The study of the interchange of chemical and electrical energy.
Chapter 13: Electrochemistry Redox Reactions Galvanic Cells Cell Potentials Cell Potentials and Equilbrium Batteries Electrolysis Electrolysis and Stoichiometry Corrosion Prevention Electrochemistry The
APPENDIX B: EXERCISES
BUILDING CHEMISTRY LABORATORY SESSIONS APPENDIX B: EXERCISES Molecular mass, the mole, and mass percent Relative atomic and molecular mass Relative atomic mass (A r ) is a constant that expresses the ratio
Experiment 5. Chemical Reactions A + X AX AX A + X A + BX AX + B AZ + BX AX + BZ
Experiment 5 Chemical Reactions OBJECTIVES 1. To observe the various criteria that are used to indicate that a chemical reaction has occurred. 2. To convert word equations into balanced inorganic chemical
1. When the following equation is balanced, the coefficient of Al is. Al (s) + H 2 O (l)? Al(OH) 3 (s) + H 2 (g)
1. When the following equation is balanced, the coefficient of Al is. Al (s) + H 2 O (l)? Al(OH) (s) + H 2 (g) A) 1 B) 2 C) 4 D) 5 E) Al (s) + H 2 O (l)? Al(OH) (s) + H 2 (g) Al (s) + H 2 O (l)? Al(OH)
Mineral Solubility Questions
1 Mineral Solubility Questions The solubility product (K sp ) of a solid has an important function: it tells us whether the solid will dissolve, and if so the resulting concentrations, or precipitate.
Name AP CHEM / / Collected Essays Chapter 17 Answers
Name AP CHEM / / Collected Essays Chapter 17 Answers 1980 - #2 M(s) + Cu 2+ (aq) M 2+ (aq) + Cu(s) For the reaction above, E = 0.740 volt at 25 C. (a) Determine the standard electrode potential for the
Formulae, stoichiometry and the mole concept
3 Formulae, stoichiometry and the mole concept Content 3.1 Symbols, Formulae and Chemical equations 3.2 Concept of Relative Mass 3.3 Mole Concept and Stoichiometry Learning Outcomes Candidates should be
B I N G O B I N G O. Hf Cd Na Nb Lr. I Fl Fr Mo Si. Ho Bi Ce Eu Ac. Md Co P Pa Tc. Uut Rh K N. Sb At Md H. Bh Cm H Bi Es. Mo Uus Lu P F.
Hf Cd Na Nb Lr Ho Bi Ce u Ac I Fl Fr Mo i Md Co P Pa Tc Uut Rh K N Dy Cl N Am b At Md H Y Bh Cm H Bi s Mo Uus Lu P F Cu Ar Ag Mg K Thomas Jefferson National Accelerator Facility - Office of cience ducation
Physical Changes and Chemical Reactions
Physical Changes and Chemical Reactions Gezahegn Chaka, Ph.D., and Sudha Madhugiri, Ph.D., Collin College Department of Chemistry Objectives Introduction To observe physical and chemical changes. To identify
Chapter 17. How are acids different from bases? Acid Physical properties. Base. Explaining the difference in properties of acids and bases
Chapter 17 Acids and Bases How are acids different from bases? Acid Physical properties Base Physical properties Tastes sour Tastes bitter Feels slippery or slimy Chemical properties Chemical properties
Solubility Product Constant
Solubility Product Constant Page 1 In general, when ionic compounds dissolve in water, they go into solution as ions. When the solution becomes saturated with ions, that is, unable to hold any more, the
EXPERIMENT 8: Activity Series (Single Displacement Reactions)
EPERIMENT 8: Activity Series (Single Displacement Reactions) PURPOSE a) Reactions of metals with acids and salt solutions b) Determine the activity of metals c) Write a balanced molecular equation, complete
Chapter 8 - Chemical Equations and Reactions
Chapter 8 - Chemical Equations and Reactions 8-1 Describing Chemical Reactions I. Introduction A. Reactants 1. Original substances entering into a chemical rxn B. Products 1. The resulting substances from
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
Chemistry 1C-Dr. Larson Chapter 20 Review Questions MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) is reduced in the following reaction: Cr2O7
Atoms and Elements. Atoms: Learning Goals. Chapter 3. Atoms and Elements; Isotopes and Ions; Minerals and Rocks. Clicker 1. Chemistry Background?
Chapter 3 Atoms Atoms and Elements; Isotopes and Ions; Minerals and Rocks A Review of Chemistry: What geochemistry tells us Clicker 1 Chemistry Background? A. No HS or College Chemistry B. High School
6 Reactions in Aqueous Solutions
6 Reactions in Aqueous Solutions Water is by far the most common medium in which chemical reactions occur naturally. It is not hard to see this: 70% of our body mass is water and about 70% of the surface
4.3 Reaction Stoichiometry
196 Chapter 4 Stoichiometry of Chemical Reactions 4.3 Reaction Stoichiometry By the end of this section, you will be able to: Explain the concept of stoichiometry as it pertains to chemical reactions Use
Galvanic cell and Nernst equation
Galvanic cell and Nernst equation Galvanic cell Some times called Voltaic cell Spontaneous reaction redox reaction is used to provide a voltage and an electron flow through some electrical circuit When
Discovering Electrochemical Cells
Discovering Electrochemical Cells Part I Electrolytic Cells Many important industrial processes PGCC CHM 102 Cell Construction e e power conductive medium What chemical species would be present in a vessel
Answers and Solutions to Text Problems
Chapter 7 Answers and Solutions 7 Answers and Solutions to Text Problems 7.1 A mole is the amount of a substance that contains 6.02 x 10 23 items. For example, one mole of water contains 6.02 10 23 molecules
CHM1 Review Exam 12. Topics REDOX
CHM1 Review Exam 12 Topics REDOX REDOX Reactions Oxidation Reduction Oxidizing agent Reducing agent Galvanic (Voltaic) Cells Anode Cathode Salt bridge Electrolyte Half-reactions Voltage o Positive voltages
AP Chemistry 2009 Free-Response Questions Form B
AP Chemistry 009 Free-Response Questions Form B The College Board The College Board is a not-for-profit membership association whose mission is to connect students to college success and opportunity. Founded
Solution a homogeneous mixture = A solvent + solute(s) Aqueous solution water is the solvent
Solution a homogeneous mixture = A solvent + solute(s) Aqueous solution water is the solvent Water a polar solvent: dissolves most ionic compounds as well as many molecular compounds Aqueous solution:
HOMEWORK 4A. Definitions. Oxidation-Reduction Reactions. Questions
HOMEWORK 4A Oxidation-Reduction Reactions 1. Indicate whether a reaction will occur or not in each of following. Wtiring a balcnced equation is not necessary. (a) Magnesium metal is added to hydrochloric
Chapter 7: Chemical Reactions
Chapter 7 Page 1 Chapter 7: Chemical Reactions A chemical reaction: a process in which at least one new substance is formed as the result of a chemical change. A + B C + D Reactants Products Evidence that
Chemistry Ch 15 (Solutions) Study Guide Introduction
Chemistry Ch 15 (Solutions) Study Guide Introduction Name: Note: a word marked (?) is a vocabulary word you should know the meaning of. A homogeneous (?) mixture, or, is a mixture in which the individual
CHAPTERS 15 FAKE TEST QUESTIONS. 1. According to the Brønsted Lowry definition, which species can function both as an acid and as a base?
You might need to know the following K values: CHAPTERS 15 FAKE TEST QUESTIONS CH 3 COOH K a = 1.8 x 10 5 Benzoic Acid K a = 6.5 x 10 5 HNO 2 K a = 4.5 x 10 4 NH 3 K b = 1.8 x 10 5 HF K a = 7.2 x 10 4
Electrochemistry Worksheet
Electrochemistry Worksheet 1. Assign oxidation numbers to each atom in the following: a. P 4 O 6 b. BiO 3 c. N 2 H 4 d. Mg(BrO 4 ) 2 e. MnSO 4 f. Mn(SO 4 ) 2 2. For each of the reactions below identify
CHEMICAL REACTIONS. Chemistry 51 Chapter 6
CHEMICAL REACTIONS A chemical reaction is a rearrangement of atoms in which some of the original bonds are broken and new bonds are formed to give different chemical structures. In a chemical reaction,
дл X АКАяOOдлАмOOдлАм Y АКдл АК E АВАВАяАя
АК E длак Ая OOАВOАсдлАмАя E OАя АяO АК E длoавак A дл X АКАяOOдлАмOOдлАм Y АКдл АК E АВАВАяАя fi А applefi АУ apple apple- Ая. Аяfi fi Ая, Ав АУ appleау Ая apple - АУ. АК apple apple Авfi apple, АУ appleав
UNITS OF CONCENTRATION
UNITS OF CONCENTRATION There are a number of different ways of expressing solute concentration that are commonly used. Some of these are listed below. Molarity, M = moles solute/liter of solution Normality,
Chemistry B11 Chapter 4 Chemical reactions
Chemistry B11 Chapter 4 Chemical reactions Chemical reactions are classified into five groups: A + B AB Synthesis reactions (Combination) H + O H O AB A + B Decomposition reactions (Analysis) NaCl Na +Cl
4.1 Stoichiometry. 3 Basic Steps. 4. Stoichiometry. Stoichiometry. Butane Lighter 2C 4 H 10 + 13O 2 10H 2 O + 8CO 2
4. Stoichiometry 1. Stoichiometric Equations 2. Limiting Reagent Problems 3. Percent Yield 4. Limiting Reagent Problems 5. Concentrations of Solutes 6. Solution Stoichiometry 7. ph and Acid Base Titrations
SCH 4C1 Unit 2 Problem Set Questions taken from Frank Mustoe et all, "Chemistry 11", McGraw-Hill Ryerson, 2001
SCH 4C1 Unit 2 Problem Set Questions taken from Frank Mustoe et all, "Chemistry 11", McGraw-Hill Ryerson, 2001 1. A small pin contains 0.0178 mol of iron. How many atoms of iron are in the pin? 2. A sample
Cambridge International Examinations Cambridge International Advanced Subsidiary and Advanced Level
Cambridge International Examinations Cambridge International Advanced Subsidiary and Advanced Level *0123456789* CHEMISTRY 9701/02 Paper 2 AS Level Structured Questions For Examination from 2016 SPECIMEN
Final. Mark Scheme. Chemistry CHEM5. (Specification 2420) Unit 5: Energetics, Redox and Inorganic Chemistry
Version.2 General Certificate of Education (A-level) January 202 Chemistry CHEM5 (Specification 2420) Unit 5: Energetics, Redox and Inorganic Chemistry Final Mark Scheme Mark schemes are prepared by the
Ch 8.5 Solution Concentration Units % (m/m or w/w) = mass of solute x 100 total mass of solution mass of solution = mass solute + mass solvent
1 Ch 8.5 Solution Concentration Units % (m/m or w/w) = mass of solute x 100 total mass of solution mass of solution = mass solute + mass solvent % (v/v) = volume of solute x 100 volume of solution filled
Write the acid-base equilibria connecting all components in the aqueous solution. Now list all of the species present.
Chapter 16 Acids and Bases Concept Check 16.1 Chemists in the seventeenth century discovered that the substance that gives red ants their irritating bite is an acid with the formula HCHO 2. They called
12. REDOX EQUILIBRIA
12. REDOX EQUILIBRIA The electrochemical series (reference table) 12.1. Redox reactions 12.2. Standard electrode potentials 12.3. Calculations involving electrochemical cells 12.4. Using Eʅ values to predict
AP Chemistry 2006 Free-Response Questions
AP Chemistry 006 Free-Response Questions The College Board: Connecting Students to College Success The College Board is a not-for-profit membership association whose mission is to connect students to college
Soil Chemistry Ch. 2. Chemical Principles As Applied to Soils
Chemical Principles As Applied to Soils I. Chemical units a. Moles and Avogadro s number The numbers of atoms, ions or molecules are important in chemical reactions because the number, rather than mass