CMY 117 SEMESTERTOETS 2 / SEMESTER TEST 2
|
|
- Cameron Stewart
- 7 years ago
- Views:
Transcription
1 DEPARTEMENT CHEMIE DEPARTMENT OF CHEMISTRY CMY 117 SEMESTERTOETS 2 / SEMESTER TEST 2 DATUM / DATE: 13 May / Mei 2013 PUNTE / MARKS: 100 TYD / TIME: 3 ure / hours Afdeling A / Section A: 40 Afdeling B / Section B: 60 ************************************ AFDELING A / SECTION A Memorandum VAN EN VOORLETTERS: SURNAME AND INITIALS: REGISTRASIENOMMER: GRAADKURSUS: REGISTRATION NUMBER: DEGREE COURSE: HANDTEKENING / SIGNATURE : VRAAG QUESTION PUNTE MARKS 1 10 EKSAMINATOR EXAMINER TOTAAL: AFDELING A TOTAL: SECTION A 40 TOTAAL: AFDELING B TOTAL: SECTION B 60 TOTAAL / TOTAL 100 INSTRUCTIONS All answers (calculations, sketches, and diagrams) must be given in ink. All calculations must be shown in full. Answers must be given to the correct number of significant figures. An information page is attached to Section B. INSTRUKSIES Alle berekeninge, sketse en diagramme moet in ink gegee word. Alle berekeninge moet volledig getoon word. Antwoorde moet tot die korrekte aantal betekenisvolle syfers gegee word. n Datablad is aangeheg aan Afdeling B.
2 Question 1 Dilutions and Titrations [10] Vraag 1 Verdunnings en Titrasies [10] The concentration of a given dm 3 solution of phosphoric acid (H 3 PO 4 ) must be determined. The following procedure was carried out in the laboratory: cm 3 of the given solution was transferred with a pipette into an empty cm 3 volumetric flask. Distilled water was added to the graduation mark of this volumetric flask. The content of the flask was well mixed cm 3 of the solution of the volumetric flask was transferred with a pipette into an empty conical flask. Indicator was added to this solution. The content of the conical flask was titrated with a mol.dm 3 solution of sodium hydroxide. At the endpoint of the titration the reading on the burette was cm 3. From this information, calculate the concentration of the given solution of phosphoric acid in mol.dm 3. [10] Die konsentrasie van n gegewe dm 3 oplossing van fosforsuur (H 3 PO 4 ) moet bepaal word. Die volgende prosedure was in die laboratorium uitgevoer: cm 3 van die gegewe oplossing was oorgedra met n pipet in leë cm 3 volumetriese fles. Gedistilleerde water was bygevoeg tot by die ykmerk van die volumetriese fles. Die inhoud van die fles was goed gemeng cm 3 van die oplossing van die volumetriese fles was oorgedra met n pipet in n koniese fles. Indikator was bygevoeg by hierdie oplossing. Die inhoud van die koniese fles was getitreer met n mol.dm 3 natriumhidroksied-oplossing. By die endpunt van die titrasie was die lesing op die buret cm 3. Met hierdie inligting, bereken die konsentrasie van die gegewe oplossing van fosforsuur in mol.dm 3. [10] CMY / 8 University of Pretoria
3 If necessary, continue on the next page. Indien nodig, gaan voort op die volgende bladsy. H 3 PO 4 (aq) + 3NaOH(aq) Na 3 PO 4 (aq) + 3H 2 O(l) Balanced equation Plan: titre mol NaOH mol H3PO4 in 20 ml 250/20 mol in 250 ml 5000/15 mol in 5L C=n/V [H3PO4]5L or Balanced equation Plan: titre mol NaOH mol C=n/V H3PO4 [H3PO4]20.00 ml = dilution [H3PO4]250mL [H3PO4]5L Mol NaOH: e = C V = = mol NqOH Mol H 3 PO 4 in conical flask: mol 1 = mol (from balanced equation) 3 Mol H 3 PO 4 in ml flask: mol = mol Mol H 3 PO 4 in 5.00 dm 3 flask: mol = mol [H 3 PO 4 ] in 5.00 L flask: C = n 12.5 mol = = mol V dm 3 dm 0 or M or C = n mol = V dm3 = mol qm 3 Concentration of solution in cm 3 flask is M or C A V A C B V B = n A n B = 1 3 C A = 1 3 C BV B V A = M cm3 = M cm 3 e = C V = = mol in cm 3 flask C = n mol = = mol V dm 3 dm 0 or M or C 1 V 1 = C 2 V 2 C 1 (15.00 qm 3 ) = ( M)( qm 3 ) C 1 = mol dm 0 or M CMY / 8 University of Pretoria
4 Question 2 Bonding and Molecular Structure [10] Vraag 2 Binding en Molekulêre Geometrie [10] Consider the XeO 2 F 2 molecule. 2.1 By using only single bonds, draw the Lewis Structure of this molecule. Use different symbols for the valence electrons of the various atoms. Do not use dashes for bonds. Show all bonding electrons and lone electron pairs. [2] Beskou die XeO 2 F 2 molekule. 2.1 Deur slegs enkelbindings te gebruik, teken die Lewisstruktuur van hierdie molekule. Gebruik verskillende simbole vir die valenselektrone van die verskillende atome. Moet nie strepies vir bindings gebruik nie. Wys alle bindingselektrone en alleen elektronpare. [2] Atom / Atoom Formal charge / Formele lading O -1 O -1 F 0 F 0 Xe +2 [2] 2.2 Calculate the formal charge of each atom in your structure in question 2.1. Write the values in the table above. 2.3 Modify the Lewis Structure of your answer in 2.1 by taking the tendencies of formal charges into account. [3] 2.2 Bereken die formele lading van elke atoom in jou struktuur in vraag 2.1. Skryf die waardes in die tabel hierbo. 2.3 Verander die Lewisstruktuur van jou antwoord in vraag 2.1 deur die neigings van formele ladings in ag te neem. [3] Atom / Atoom Formal charge / Formele lading O 0 O 0 F 0 F 0 Xe 0 [1] 2.4 Calculate the formal charge of each atom in your Lewis Structure in question 2.3. Write the values in the table above. 2.5 Give the names of the following of the structure in question 2.3: Electron pair geometry: Trigonal bipyramidal [1] Molecular geometry: See-saw [1] 2.4 Bereken die formele lading van elke atoom in jou struktuur in vraag 2.3. Skryf die waardes in die tabel hierbo. 2.5 Gee die name van die volgende in die struktuur in vraag 2.3: Elektronpaargeometrie: Trigonaal bipiramidaal [1] Molekulêre geometrie: Wipplank [1] CMY / 8 University of Pretoria
5 Question 3 Kinetics [10] Vraag 3 Kinetika [10] Consider the following reaction: Beskou die volgende reaksie: To obtain the rate law for this reaction, the following experiments were run. For each experiment the initial rate of reaction for NO was determined. Experiment no. / nr. 2NO(g) + 2H 2 (g) N 2 (g) + 2H 2 O(g) [NO] 0 (mol/l) Om die tempowet vir hierdie reaksie te bepaal, is die volgende eksperimente gedoen. Vir elke eksperiment is die aanvangstempo van reaksie vir NO bepaal. [H 2 ] 0 (mol/l) Initial rate for NO Aanvangstempo vir NO (mol L -1 s -1 ) Determine the rate law. [Hint: determine the order for H 2 first] [7] 3.1 Bepaal die tempowet. [Wenk: bepaal eers die orde vir H 2 ] [7] The rate law will have the following format: oqqe = k[no] x [H 2 ] y Comparing experiments 1 and 2: When [H 2 ] 0 triples, the rate is = 3 times faster Conclusion: the reaction is first order in H 2 and y = 0 or Order with respect to NO: o 2 = k[no]x [H 2 ] y o 1 k[no] x [H 2 ] y = k[0.0200]x (0.0900) y k[0.0200] x (0.0300) y y = = 3 y y = 0 o 3 = k[no]x [H 2 ] y o 2 k[no] x [H 2 ] y = k[0.0350]x (0.0350) 1 k[0.0200] x (0.0900) 1 x = = 1.75 x x = lol3.059 lol1.75 = Rqqe lqw: rate = k[no] 2 [H 2 ] CMY / 8 University of Pretoria
6 3.2 Determine the value and unit of the rate constant. [3] 3.2 Bepaal die waarde en eenheid van die tempokonstante. [3] Carry rate law from 3.1 Use any experiment, e.g. experiment 1: Experimental rate was given for NO rate of reaction = 1 2 From the rate law: [NO] t = 1 ( ) = mol 2 L 1 s 1 1 if rate not halved mol L 1 s 1 = k ( mol L 1 ) 2 ( mol L 1 ) OR Experiment 2: k = mol L 1 s mol 3 L 3 = 005 mol 2 L 2 s 0 oo 005 mol 2 dm 6 s 0 oo 005 M 2 s 0 k = mol L 1 s mol 3 L 3 = 005 mol 2 L 2 s OR Experiment 3: k = mol L 1 s mol 3 L 3 = 005 mol 2 L 2 s 0 CMY / 8 University of Pretoria
7 Question 4 Chemical Equilibrium [10] Vraag 4 Chemiese Ewewig [10] mol of CO 2 (g) and mol CF 4 (g) are mixed in a L container at 120. The following reaction takes place: 4.1 At equilibrium the COF 2 concentration is M. What is the value of the equilibrium constant? [4] mol CO 2 (g) en mol CF 4 (g) word in ʼn L houer by 120 gemeng. Die volgende reaksie vind plaas: CO 2 (g) + CF 4 (g) 2COF 2 (g) 4.1 By ewewig is die COF 2 konsentrasie M. Wat is die waarde van die ewewigskonstante? [4] CO 2 + CF 4 2COF 2 I (M) C (M) E (M) K c = [COF 2] 2 [CO 2 ][CF 4 ] = = or in terms of moles: CO 2 + CF 4 2COF 2 I (mol) C (mol) E (mol) E (M) K c = [COF 2] 2 [CO 2 ][CF 4 ] = = CMY / 8 University of Pretoria
8 4.2 The above equilibrium is disturbed by adding mol COF 2 to this equilibrium mixture, still at 120. What will the concentrations of both reactants and product be when equilibrium is reestablished? [6] 4.2 Die bostaande ewewig word versteur deur mol COF 2 by die ewewigmengsel te voeg, steeds by 120. Wat sal die konsentrasies van beide reagense en produk wees wanneer die ewewig herstel is? [6] Carry equilibrium concentrations from 4.1 CO 2 + CF 4 2COF 2 E (M) Disturb (M) I (M) C (M) +x +x 2x E (M) x x x K c = = [COF 2] 2 = ( x)2 [CO 2 ][CF 4 ] ( x) x = = x ( x) = x x + 2x = x = x = oo qqqqqqqqq eeeeeeee: 3.265x x = 0 x = b ± b2 4aa 2a x = (ttt lllll) oo x = [CO 2 ] = [CF 4 ] = x = M [COF 2 ] = x = M AFDELING B / SECTION B Answers / Antwoorde # Answer C H C F E D C A A B C B E C I H D E B B B C D F A A F E CMY / 8 University of Pretoria
UNIVERSITEIT VAN PRETORIA / UNIVERSITY OF PRETORIA DEPT WISKUNDE EN TOEGEPASTE WISKUNDE DEPT OF MATHEMATICS AND APPLIED MATHEMATICS
VAN/SURNAME: UNIVERSITEIT VAN PRETORIA / UNIVERSITY OF PRETORIA DEPT WISKUNDE EN TOEGEPASTE WISKUNDE DEPT OF MATHEMATICS AND APPLIED MATHEMATICS VOORNAME/FIRST NAMES: WTW 162 DYNAMICAL PROCESSES EKSAMEN
More informationAcid-Base Titrations. Setup for a Typical Titration. Titration 1
Titration 1 Acid-Base Titrations Molarities of acidic and basic solutions can be used to convert back and forth between moles of solutes and volumes of their solutions, but how are the molarities of these
More informationDepartment of Mathematics and Applied Mathematics Departement Wiskunde en Toegepaste Wiskunde
Department of Mathematics and Applied Mathematics Departement Wiskunde en Toegepaste Wiskunde MATHEMATICS COMPETITION WISKUNDE KOMPETISIE GRADES 0 AND GRADE 0 EN SEPTEMBER 04 SEPTEMBER 04 TIME: HOURS TYD:
More informationThe Determination of Acid Content in Vinegar
The Determination of Acid Content in Vinegar Reading assignment: Chang, Chemistry 10 th edition, pages 153-156. Goals We will use a titration to determine the concentration of acetic acid in a sample of
More informationTutorial 4 SOLUTION STOICHIOMETRY. Solution stoichiometry calculations involve chemical reactions taking place in solution.
T-27 Tutorial 4 SOLUTION STOICHIOMETRY Solution stoichiometry calculations involve chemical reactions taking place in solution. Of the various methods of expressing solution concentration the most convenient
More informationSolution 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:
More informationPaper 1 (7404/1): Inorganic and Physical Chemistry Mark scheme
AQA Qualifications AS Chemistry Paper (7404/): Inorganic and Physical Chemistry Mark scheme 7404 Specimen paper Version 0.6 MARK SCHEME AS Chemistry Specimen paper Section A 0. s 2 2s 2 2p 6 3s 2 3p 6
More informationn molarity = M = N.B.: n = litres (solution)
1. CONCENTRATION UNITS A solution is a homogeneous mixture of two or more chemical substances. If we have a solution made from a solid and a liquid, we say that the solid is dissolved in the liquid and
More informationVermenigvuldig en Afdeling (Intermediêre fase)
Vermenigvuldig en Afdeling (Intermediêre fase) My Huiswerk Boek(4) Naam: Jaar: Skool: Declaration This booklet is not sold or used for profit making. It is used solely for educational purposes. You may
More informationInstructions Answer all questions in the spaces provided. Do all rough work in this book. Cross through any work you do not want to be marked.
GCSE CHEMISTRY Higher Tier Chemistry 1H H Specimen 2018 Time allowed: 1 hour 45 minutes Materials For this paper you must have: a ruler a calculator the periodic table (enclosed). Instructions Answer all
More informationDepartment of Mathematics and Applied Mathematics Departement Wiskunde en Toegepaste Wiskunde
Department of Mathematics and Applied Mathematics Departement Wiskunde en Toegepaste Wiskunde MATHEMATICS COMPETITION WISKUNDE KOMPETISIE GRADES 8 AND 9 GRADE 8 EN 9 SEPTEMBER 204 SEPTEMBER 204 TIME: 2
More informationNATIONAL SENIOR CERTIFICATE GRADE/GRAAD 12
NATIONAL SENI CERTIFICATE GRADE/GRAAD MATHEMATICS P/WISKUNDE V EXEMPLAR 0/MODEL 0 MEMANDUM MARKS: 0 PUNTE: 0 This memandum consists of pages. Hierdie memandum bestaan uit bladse. Mathematics P/Wiskunde
More informationDie vrae uit ou vraestelle, toetsvraestelle, en modelvraestelle is individueel gekies en uitgehaal vir
Die vrae uit ou vraestelle, toetsvraestelle, en modelvraestelle is individueel gekies en uitgehaal vir Kategorisering Dieselfde vraag kan by meer as een afdeling van die sillabus voorkom, of meer as een
More informationAcetic Acid Content of Vinegar: An Acid-Base Titration E10-1
Experiment 10 Acetic Acid Content of Vinegar: An Acid-Base Titration E10-1 E10-2 The task The goal of this experiment is to determine accurately the concentration of acetic acid in vinegar via volumetric
More informationAP Chemistry 2005 Scoring Guidelines Form B
AP Chemistry 2005 Scoring Guidelines Form B 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
More informationGCE Chemistry PSA14: A2 Physical Chemistry Determine an equilibrium contstant
hij Teacher Resource Bank GCE Chemistry : A2 Physical Chemistry Determine an equilibrium contstant Copyright 2009 AQA and its licensors. All rights reserved. The Assessment and Qualifications Alliance
More informationDETERMINATION OF PHOSPHORIC ACID CONTENT IN SOFT DRINKS
DETERMINATION OF PHOSPHORIC ACID CONTENT IN SOFT DRINKS LAB PH 8 From Chemistry with Calculators, Vernier Software & Technology, 2000 INTRODUCTION Phosphoric acid is one of several weak acids that present
More informationAP 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
More informationBalance the following equation: KClO 3 + C 12 H 22 O 11 KCl + CO 2 + H 2 O
Balance the following equation: KClO 3 + C 12 H 22 O 11 KCl + CO 2 + H 2 O Ans: 8 KClO 3 + C 12 H 22 O 11 8 KCl + 12 CO 2 + 11 H 2 O 3.2 Chemical Symbols at Different levels Chemical symbols represent
More information15. Acid-Base Titration. Discover the concentration of an unknown acid solution using acid-base titration.
S HIFT INTO NEUTRAL 15. Acid-Base Titration Shift into Neutral Student Instruction Sheet Challenge Discover the concentration of an unknown acid solution using acid-base titration. Equipment and Materials
More informationph: 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
More informationVolumetric Analysis. Lecture 5 Experiment 9 in Beran page 109 Prelab = Page 115
Volumetric Analysis Lecture 5 Experiment 9 in Beran page 109 Prelab = Page 115 Experimental Aims To prepare and standardize (determine concentration) a NaOH solution Using your standardized NaOH calculate
More informationIB Chemistry. DP Chemistry Review
DP Chemistry Review Topic 1: Quantitative chemistry 1.1 The mole concept and Avogadro s constant Assessment statement Apply the mole concept to substances. Determine the number of particles and the amount
More informationThe introduction of your report should be written on the on the topic of the role of indicators on acid base titrations.
Experiment # 13A TITRATIONS INTRODUCTION: This experiment will be written as a formal report and has several parts: Experiment 13 A: Basic methods (accuracy and precision) (a) To standardize a base (~
More informationChemistry: 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,
More informationstoichiometry = 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
More information(1) Hydrochloric acid reacts with sodium hypochlorite to form hypochlorous acid: NaOCl(aq) + HCl(aq) HOCl(aq) + NaCl(aq) hypochlorous acid
The Determination of Hypochlorite in Bleach Reading assignment: Chang, Chemistry 10 th edition, pages 156-159. We will study an example of a redox titration in order to determine the concentration of sodium
More informationIMPLEMENTING AN EFFECTIVE INFORMATION SECURITY AWARENESS PROGRAM
IMPLEMENTING AN EFFECTIVE INFORMATION SECURITY AWARENESS PROGRAM by AMANDA WOLMARANS DISSERTATION Submitted in fulfilment of the requirements for the degree MASTER OF SCIENCE in COMPUTER SCIENCE in the
More informationCHEMISTRY 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
More informationSyllabus OC18 Use litmus or a universal indicator to test a variety of solutions, and classify these as acidic, basic or neutral
Chemistry: 9. Acids and Bases Please remember to photocopy 4 pages onto one sheet by going A3 A4 and using back to back on the photocopier Syllabus OC18 Use litmus or a universal indicator to test a variety
More informationFormulas, Equations and Moles
Chapter 3 Formulas, Equations and Moles Interpreting Chemical Equations You can interpret a balanced chemical equation in many ways. On a microscopic level, two molecules of H 2 react with one molecule
More informationDetermination of the Amount of Acid Neutralized by an Antacid Tablet Using Back Titration
Determination of the Amount of Acid Neutralized by an Antacid Tablet Using Back Titration GOAL AND OVERVIEW Antacids are bases that react stoichiometrically with acid. The number of moles of acid that
More informationNATIONAL SENIOR CERTIFICATE/ NASIONALE SENIOR SERTIFIKAAT GRADE/GRAAD 12 SEPTEMBER 2014 MATHEMATICS P1/WISKUNDE V1 MEMORANDUM
NATIONAL SENIOR CERTIFICATE/ NASIONALE SENIOR SERTIFIKAAT GRADE/GRAAD 12 SEPTEMBER 2014 MATHEMATICS P1/WISKUNDE V1 MEMORANDUM MARKS/PUNTE: 150 Hierdie memorandum bestaan uit 16 bladsye./ This memorandum
More informationhij Teacher Resource Bank GCE Chemistry PSA10: A2 Inorganic Chemistry Carry out a redox titration
hij Teacher Resource Bank GCE Chemistry : A2 Inorganic Chemistry Copyright 2009 AQA and its licensors. All rights reserved. The Assessment and Qualifications Alliance (AQA) is a company limited by guarantee
More informationTopic 18 Acids and Bases. 18.1 Exercises
Topic 18 Acids and Bases 18.1 Exercises 1. Define: (a) ph The negative log of the hydrogen ion concentration in a solution. i.e. ph = log[h 3 O + ] (b) poh The negative log of hydroxide ion concentration
More informationFormulae, 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
More informationLab #10 How much Acetic Acid (%) is in Vinegar?
Lab #10 How much Acetic Acid (%) is in Vinegar? SAMPLE CALCULATIONS NEED TO BE DONE BEFORE LAB MEETS!!!! Purpose: You will determine the amount of acetic acid in white vinegar (sold in grocery stores)
More informationMEMORANDUM GRADE 11. PHYSICAL SCIENCES: CHEMISTRY Paper 2
MEMORANDUM GRADE 11 PHYSICAL SCIENCES: CHEMISTRY Paper 2 MARKS: 150 TIME: 3 hours Learning Outcomes and Assessment Standards LO1 LO2 LO3 AS 11.1.1: Plan and conduct a scientific investigation to collect
More informationWrite 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
More informationTo see how this data can be used, follow the titration of hydrofluoric acid against sodium hydroxide below. HF (aq) + NaOH (aq) H2O (l) + NaF (aq)
Weak Acid Titration v120413 You are encouraged to carefully read the following sections in Tro (2 nd ed.) to prepare for this experiment: Sec 4.8, pp 158-159 (Acid/Base Titrations), Sec 16.4, pp 729-43
More informationName 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
More information3 The Preparation of Buffers at Desired ph
3 The Preparation of Buffers at Desired ph Objectives: To become familiar with operating a ph meter, and to learn how to use the Henderson-Hasselbalch equation to make buffer solutions at a desired ph
More informationEXPERIMENT 10: TITRATION AND STANDARDIZATION
EXPERIMENT 10: TITRATION AND STANDARDIZATION PURPOSE To determine the molarity of a NaOH solution by titrating it with a standard HCl solution. To determine the molarity of acetic acid in vinegar using
More informationChemical Equations and Chemical Reactions. Chapter 8.1
Chemical Equations and Chemical Reactions Chapter 8.1 Objectives List observations that suggest that a chemical reaction has taken place List the requirements for a correctly written chemical equation.
More informationAqueous 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
More informationDetermining the Identity of an Unknown Weak Acid
Purpose The purpose of this experiment is to observe and measure a weak acid neutralization and determine the identity of an unknown acid by titration. Introduction The purpose of this exercise is to identify
More informationStoichiometry. Lecture Examples Answer Key
Stoichiometry Lecture Examples Answer Key Ex. 1 Balance the following chemical equations: 3 NaBr + 1 H 3 PO 4 3 HBr + 1 Na 3 PO 4 2 C 3 H 5 N 3 O 9 6 CO 2 + 3 N 2 + 5 H 2 O + 9 O 2 2 Ca(OH) 2 + 2 SO 2
More informationWe remember that molarity (M) times volume (V) is equal to moles so this relationship is the definition of the equivalence point.
Titrations Titration - a titration is defined as the determination of the amount of an unknown reagent (analyte) through the use of a known amount of another reagent (titrant) in an essentially irreversible
More informationAP Chemistry 2010 Scoring Guidelines Form B
AP Chemistry 2010 Scoring Guidelines 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
More informationChapter 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
More informationTopic 4 National Chemistry Summary Notes. Formulae, Equations, Balancing Equations and The Mole
Topic 4 National Chemistry Summary Notes Formulae, Equations, Balancing Equations and The Mole LI 1 The chemical formula of a covalent molecular compound tells us the number of atoms of each element present
More informationAcid-Base Chemistry. Brønsted-Lowry Acids & Bases
Acid-Base Chemistry ν There are a couple of ways to define acids and bases ν Brønsted-Lowry acids and bases ν Acid: H + ion donor ν Base: H + ion acceptor ν Lewis acids and bases ν Acid: electron pair
More informationC has 4 valence electrons, O has six electrons. The total number of electrons is 4 + 2(6) = 16.
129 Lewis Structures G. N. Lewis hypothesized that electron pair bonds between unlike elements in the second (and sometimes the third) row occurred in a way that electrons were shared such that each element
More informationCh 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
More information4.1 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
More informationCHAPTERS 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
More informationJuice Titration. Background. Acid/Base Titration
Juice Titration Background Acids in Juice Juice contains both citric and ascorbic acids. Citric acid is used as a natural preservative and provides a sour taste. Ascorbic acid is a water-soluble vitamin
More informationAP CHEMISTRY 2013 SCORING GUIDELINES
AP CHEMISTRY 2013 SCORING GUIDELINES Question 4 (15 points) For each of the following three reactions, write a balanced equation for the reaction in part (i) and answer the question about the reaction
More informationI N V E S T I C E D O R O Z V O J E V Z D Ě L Á V Á N Í CHEMICAL REACTIONS
Chemical reaction = process during which original substances change to new substances, reactants turn to... The bonds of reactants... and new bonds are... The classification of reactions: 1. Classification
More informationChemistry 151 Final Exam
Chemistry 151 Final Exam Name: SSN: Exam Rules & Guidelines Show your work. No credit will be given for an answer unless your work is shown. Indicate your answer with a box or a circle. All paperwork must
More informationSOLID STATE CHEMISTRY - SURFACE ADSORPTION
SOLID STATE CHEMISTRY - SURFACE ADSORPTION BACKGROUND The adsorption of molecules on the surfaces of solids is a very interesting and useful phenomenon. Surface adsorption is at the heart of such things
More information1. Read P. 368-375, P. 382-387 & P. 429-436; P. 375 # 1-11 & P. 389 # 1,7,9,12,15; P. 436 #1, 7, 8, 11
SCH3U- R.H.KING ACADEMY SOLUTION & ACID/BASE WORKSHEET Name: The importance of water - MAKING CONNECTION READING 1. Read P. 368-375, P. 382-387 & P. 429-436; P. 375 # 1-11 & P. 389 # 1,7,9,12,15; P. 436
More informationHow To Get A Bsc In Forensic Science
DEPARTEMENT GENETIKA / DEPARTMENT OF GENETICS Keuringsaansoek: BSc Forensiese Wetenskappe / Selection Application: BSc Forensic Science Applying for BSc Forensic Science (Die Afrikaanse inligtingstuk vir
More informationPolicy on Student Leadership Development and Training
Department of Student Affairs (DSA) Policy on Student Leadership Development and Training Document type: Policy Document number: Rt 461/10 1. PURPOSE 1.1.1 Background It is the mission of UP to deliver
More informationChemistry CA 2 Practice
hemistry 2 Practice Some questions (c) 2015 by Region 10 Educational Service enter. Some questions (c) 2015 by Progress Testing. Page 2 1 Which of the following is the mass in grams of 4.25 10³ mol of
More informationChemistry 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
More informationDetermination of Citric Acid in Powdered Drink Mixes
Determination of Citric Acid in Powdered Drink Mixes Citric acid and its salts (sodium citrate and potassium citrate) are found in many foods, drinks, pharmaceuticals, shampoos, and cosmetics. The tartness
More informationUNIT (6) ACIDS AND BASES
UNIT (6) ACIDS AND BASES 6.1 Arrhenius Definition of Acids and Bases Definitions for acids and bases were proposed by the Swedish chemist Savante Arrhenius in 1884. Acids were defined as compounds that
More informationGuide To Preparation of Stock Standard Solutions
chemias ft Guide To Preparation of Stock Standard Solutions First Edition May 2011 Na+ 1000 ppm Guide To Preparation Of Stock Standard Solutions By: CHEMIASOFT May 2011 Page 2 of 61 Page 3 of 61 Table
More informationAcid-Base Titrations Using ph Measurements
Acid-Base Titrations Using ph Measurements Introduction According to the Brønsted Lowry definition, an acid is a substance that donates a hydrogen ion and a base is a substance which will accept a hydrogen
More informationChapter 1 The Atomic Nature of Matter
Chapter 1 The Atomic Nature of Matter 6. Substances that cannot be decomposed into two or more simpler substances by chemical means are called a. pure substances. b. compounds. c. molecules. d. elements.
More informationAP CHEMISTRY 2007 SCORING GUIDELINES. Question 6
AP CHEMISTRY 2007 SCORING GUIDELINES Question 6 Answer the following questions, which pertain to binary compounds. (a) In the box provided below, draw a complete Lewis electron-dot diagram for the IF 3
More informationAcid Base Titrations
Acid Base Titrations Introduction A common question chemists have to answer is how much of something is present in a sample or a product. If the product contains an acid or base, this question is usually
More informationApparatus error for each piece of equipment = 100 x margin of error quantity measured
1) Error Analysis Apparatus Errors (uncertainty) Every time you make a measurement with a piece of apparatus, there is a small margin of error (i.e. uncertainty) in that measurement due to the apparatus
More informationIB Chemistry 1 Mole. One atom of C-12 has a mass of 12 amu. One mole of C-12 has a mass of 12 g. Grams we can use more easily.
The Mole Atomic mass units and atoms are not convenient units to work with. The concept of the mole was invented. This was the number of atoms of carbon-12 that were needed to make 12 g of carbon. 1 mole
More informationACID-BASE TITRATIONS: DETERMINATION OF CARBONATE BY TITRATION WITH HYDROCHLORIC ACID BACKGROUND
#3. Acid - Base Titrations 27 EXPERIMENT 3. ACID-BASE TITRATIONS: DETERMINATION OF CARBONATE BY TITRATION WITH HYDROCHLORIC ACID BACKGROUND Carbonate Equilibria In this experiment a solution of hydrochloric
More informationLab 25. Acid-Base Titration and Neutralization Reactions: What Is the Concentration of Acetic Acid in Each Sample of Vinegar?
Lab 25. Acid-Base Titration and Neutralization Reactions: What Is the Concentration of Acetic Acid in Each Sample of Vinegar? Introduction Vinegar is basically a solution of acetic acid (CH3COOH). It is
More informationMARKETING MANAGEMENT
Faculty of Management DEPARTMENT OF MARKETING MANAGEMENT National Diploma: Marketing BCom (Marketing Managment) Department of Marketing Management Discover the world of marketing If you re wondering why
More informationChem 1B Saddleback College Dr. White 1. Experiment 8 Titration Curve for a Monoprotic Acid
Chem 1B Saddleback College Dr. White 1 Experiment 8 Titration Curve for a Monoprotic Acid Objectives To learn the difference between titration curves involving a strong acid with a strong base and a weak
More informationChemical equilibria Buffer solutions
Chemical equilibria Buffer solutions Definition The buffer solutions have the ability to resist changes in ph when smaller amounts of acid or base is added. Importance They are applied in the chemical
More informationCalculation of Molar Masses. Molar Mass. Solutions. Solutions
Molar Mass Molar mass = Mass in grams of one mole of any element, numerically equal to its atomic weight Molar mass of molecules can be determined from the chemical formula and molar masses of elements
More informationChapter 4. Chemical Composition. Chapter 4 Topics H 2 S. 4.1 Mole Quantities. The Mole Scale. Molar Mass The Mass of 1 Mole
Chapter 4 Chemical Composition Chapter 4 Topics 1. Mole Quantities 2. Moles, Masses, and Particles 3. Determining Empirical Formulas 4. Chemical Composition of Solutions Copyright The McGraw-Hill Companies,
More informationUnit 1 Chemical Changes and Structure Revision Notes
Unit 1 Revision Notes Rates of reaction The rate of reaction can be increased by: increasing the concentration of a solution decreasing the particle size of a solid increasing the temperature adding a
More informationSOLUBILITY, IONIC STRENGTH AND ACTIVITY COEFFICIENTS
SOLUBILITY, IONIC STRENGTH AND ACTIVITY COEFFICIENTS References: 1. See `References to Experiments' for text references.. W. C. Wise and C. W. Davies, J. Chem. Soc., 73 (1938), "The Conductivity of Calcium
More informationChapter 5, Calculations and the Chemical Equation
1. How many iron atoms are present in one mole of iron? Ans. 6.02 1023 atoms 2. How many grams of sulfur are found in 0.150 mol of sulfur? [Use atomic weight: S, 32.06 amu] Ans. 4.81 g 3. How many moles
More informationINTI COLLEGE MALAYSIA A? LEVEL PROGRAMME CHM 111: CHEMISTRY MOCK EXAMINATION: DECEMBER 2000 SESSION. 37 74 20 40 60 80 m/e
CHM111(M)/Page 1 of 5 INTI COLLEGE MALAYSIA A? LEVEL PROGRAMME CHM 111: CHEMISTRY MOCK EXAMINATION: DECEMBER 2000 SESSION SECTION A Answer ALL EIGHT questions. (52 marks) 1. The following is the mass spectrum
More informationYIELD YIELD REACTANTS PRODUCTS
Balancing Chemical Equations A Chemical Equation: is a representation of a chemical reaction in terms of chemical formulas Example: 1. Word Description of a Chemical Reaction When methane gas (CH 4 ) burns
More informationCHEM 105 HOUR EXAM III 28-OCT-99. = -163 kj/mole determine H f 0 for Ni(CO) 4 (g) = -260 kj/mole determine H f 0 for Cr(CO) 6 (g)
CHEM 15 HOUR EXAM III 28-OCT-99 NAME (please print) 1. a. given: Ni (s) + 4 CO (g) = Ni(CO) 4 (g) H Rxn = -163 k/mole determine H f for Ni(CO) 4 (g) b. given: Cr (s) + 6 CO (g) = Cr(CO) 6 (g) H Rxn = -26
More informationVocabulary: VSEPR. 3 domains on central atom. 2 domains on central atom. 3 domains on central atom NOTE: Valence Shell Electron Pair Repulsion Theory
Vocabulary: VSEPR Valence Shell Electron Pair Repulsion Theory domain = any electron pair, or any double or triple bond is considered one domain. lone pair = non-bonding pair = unshared pair = any electron
More informationChemical Calculations: Formula Masses, Moles, and Chemical Equations
Chemical Calculations: Formula Masses, Moles, and Chemical Equations Atomic Mass & Formula Mass Recall from Chapter Three that the average mass of an atom of a given element can be found on the periodic
More informationStoichiometry. 1. The total number of moles represented by 20 grams of calcium carbonate is (1) 1; (2) 2; (3) 0.1; (4) 0.2.
Stoichiometry 1 The total number of moles represented by 20 grams of calcium carbonate is (1) 1; (2) 2; (3) 01; (4) 02 2 A 44 gram sample of a hydrate was heated until the water of hydration was driven
More informationThe energy level diagram for this reaction is shown below.
Q. Methanol can be made when methane reacts with oxygen. (a) The energy level diagram for this reaction is shown below. (i) What is the energy change represented by A? () (ii) Use the energy level diagram
More information1. What is the molecular formula of a compound with the empirical formula PO and a gram-molecular mass of 284 grams?
Name: Tuesday, May 20, 2008 1. What is the molecular formula of a compound with the empirical formula PO and a gram-molecular mass of 284 grams? 2 5 1. P2O 5 3. P10O4 2. P5O 2 4. P4O10 2. Which substance
More informationPractical Lesson No 4 TITRATIONS
Practical Lesson No 4 TITRATIONS Reagents: 1. NaOH standard solution 0.1 mol/l 2. H 2 SO 4 solution of unknown concentration 3. Phenolphthalein 4. Na 2 S 2 O 3 standard solution 0.1 mol/l 5. Starch solution
More information2. ATOMIC, MOLECULAR AND EQUIVALENT MASSES
2. ATOMIC, MOLECULAR AND EQUIVALENT MASSES INTRODUCTION: EQUIVALENT WEIGHT Since hydrogen is the lightest of all elements, it was chosen as a standard for determination of equivalent weights. On this basis,
More informationSummer Holidays Questions
Summer Holidays Questions Chapter 1 1) Barium hydroxide reacts with hydrochloric acid. The initial concentration of the 1 st solution its 0.1M and the volume is 100ml. The initial concentration of the
More informationTo determine the equivalence points of two titrations from plots of ph versus ml of titrant added.
Titration Curves PURPOSE To determine the equivalence points of two titrations from plots of ph versus ml of titrant added. GOALS 1 To gain experience performing acid-base titrations with a ph meter. 2
More informationChemistry 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
More informationChapter 13 Chemical Kinetics
Chapter 13 Chemical Kinetics Student: 1. The units of "reaction rate" are A. L mol -1 s -1. B. L 2 mol -2 s -1. C. s -1. D. s -2. E. mol L -1 s -1. 2. For the reaction BrO 3 - + 5Br - + 6H + 3Br 2 + 3H
More information