Chemistry 105, Chapter 4 Exercises

Transcription

1 Chemistry 105, Chapter 4 Exercises Solutions and Molarity 1. What is the molarity of a ml solution containing 22.2 g of NaCl? Ans M 2. What is the molarity of NO 3 in a ml solution containing 25.0 g of Al(NO 3) 3? Ans M 3. How many grams of Ni(NO 3) 2 would be needed to prepare 2.00L of a M solution? Ans g 4. How many grams of CuCl 2 would be needed to prepare 500. ml of a 2.0 M solution? Ans g 5. How many grams of CuCl 2 would be needed to prepare 1.00 L of a M Cl solution? Ans g 6. How many grams of AlCl 3 would be needed to prepare 50.0 ml of a 2.0 M Cl solution? Ans g 7. How many milliliters of a M Al(NO 3) 3 solution are needed to furnish mole of Al(NO 3) 3? Ans ml 8. How many milliliters of a M Al(NO 3) 3 solution are needed to furnish g of Al(NO 3) 3? Ans ml 9. How many moles of Al(NO 3) 3 are present in 50.0 ml of a M solution of Al(NO 3) 3? Ans mole 10. How many moles of NO 3 are present in 10.0 ml of a M solution of Al(NO 3) 3? Ans mole 11. How many milliliters of a M solution of K 2CO 3 are needed to furnish moles of K 2CO 3? Ans ml 12. How many milliliters of a M solution of K 2CO 3 are needed to furnish 1.00 g of K 2CO 3? Ans ml 13. How many moles of K 2CO 3 are present in 25.0 ml of a M solution of K 2CO 3? Ans mole 14. How many grams of K + are present in ml of M solution of K 2CO 3? Ans g Metathesis Reactions 15. Write the molecular, complete ionic, and net ionic equations for the following reactions. Ni(NO 3) 2 + NaOH FeCl 3 + NaOH CuSO 4 + NaCl AgNO 3 + HCl Na 3PO 4 + Ba(OH)2 NH 4Cl + Ba(OH) 2 H 2SO 4 + KOH Na 2CO 3 + HNO 3 CaCl 2 + K 3PO 4 K 2S + HCl

2 Solution Stoichiometry 16. What volume of M Ba(NO 3) 2 is required to react completely with 20.0 ml of 0.937M Co 2(SO 4) 3? How many grams of precipitate will form? Ans L g Co 2(SO 4) 3(aq) + 3Ba(NO 3) 2(aq) 3BaSO 4(s) + 2Co(NO 3) 3(aq) 17. What volume of M NiSO 4 is required to react completely with 15.0 ml of M (NH 4) 2CO 3? How many grams of precipitate will form? Molar mass for NiCO 3 = g. Ans L, 1.60 g NiSO 4(aq) + (NH 4) 2CO 3(aq) NiCO 3(s) + (NH 4) 2SO 4(aq) 18. A solution of ml of M KOH is mixed with a solution of ml of M NiSO 4. How many grams of precipitate form? Molar mass for Ni(OH) 2 = 92.7 g. Ans g 2KOH(aq) + NiSO 4(aq) K 2SO 4(aq) + Ni(OH) 2(s) 19. A solution of 50.0 ml of M AlCl 3 is mixed with a solution of 35.5 ml of M Na 2CO 3. How many grams of precipitate form? Molar mass for Al 2(CO 3) 3 = 234 g. Ans g 2AlCl 3(aq) + 3Na 2CO 3(aq) Al 2(CO 3) 3(s) + 6NaCl 20. What volume of 0.500M NiSO 4 is required to react completely with 25.6 ml of M Ba(OH) 2? How many grams of precipitate will form? Ans L 2.08 g NiSO 4(aq) + Ba(OH) 2(aq) Ni(OH) 2(s) + BaSO 4(s) Balancing Neutralization Reactions 21. Complete and balance the following neutralization reaction equations. Show the molecular, complete ionic, and net ionic equations. HNO 3 + NaOH HNO 3 + Ba(OH) 2 HNO 3 + Al(OH) 3 HF + Mg(OH) 2 H 2SO 4 + KOH H 2SO 4 + Mg(OH) 2 H 2SO 4 + Al(OH) 3 H 3PO 4 + NaOH H 3PO 4 + Ca(OH) 2 H 3PO 4 + Al(OH) 3 Stoichiometry and Neutralization Reactions 22. What volume of M Sr(OH) 2 is required to neutralize ml of M HF? Ans L 23. What volume of M NaOH is required to neutralize ml of M H 2SO 4? Ans L 24. What is the molarity of a solution of HNO 3 if g of Ba(OH) 2 is required to neutralize ml of HNO 3? Molar mass for Ba(OH) 2 = g. Ans M 25. What is the molarity of a solution of H 2SO 4 if g of NaOH is required to neutralize ml of H 2SO 4? Molar mass for NaOH = 40.0 g. Ans M 26. What is the molarity of a solution of H 2SO 4 if ml of M NaOH is required to neutralize ml of the acid? Ans M

3 27. What is the molarity of a solution of H 3PO 4 if ml of M NaOH is required to neutralize ml of the acid? Ans M 28. Boric acid can be used to neutralize bases. The equation for the reaction is: H 3BO 3(s) + 2OH (aq) 2H 2O + HBO 3 2 (aq) What volume of M Ba(OH) 2 can be neutralized by g of H 3BO 3? Molar mass for H 3BO 3 = 61.8 g. Ans L 29. Some hydrochloric acid spilled on the lab floor. Sodium bicarbonate is sprinkled on the spill to neutralize the acid. NaHCO 3(s) + HCl(aq) NaCl(aq) + CO 2(g) + H 2O(l) If 75. ml of 3.00 M HCl were spilled, what is the minimum amount of NaHCO 3 that must be used to neutralize all the acid in the spill? Molar mass for NaHCO 3 = 84.0 g. Ans g OxidationReduction Reactions 30. Assign oxidation numbers to each of the elements in the following reactions. Indicate which are redox reactions. For those that are, indicate which element is oxidized and which is reduced. Cu(OH) 2 + 2HNO 3 Cu(NO 3) 2 + 2H 2O Fe 2O 3 + 3CO 2Fe + 3CO 2 Sr(NO 3) 2 + H 2SO 4 SrSO 4 + 2HNO 3 4Zn + 10H + + 2NO 3 4Zn 2+ + N 2O + 5H 2O Cl 2 + 2NaI I 2 + 2NaCl PbS + 4H 2O 2 PbSO 4 + 4H 2O 31. Use the half reaction method to balance the following reactions in acid solution. Ag + NO 3 Ag + + NO Ni 2+ + IO 4 Ni 3+ + I P 4 + Cl PH 3 + Cl 2 MnO 4 + NO 2 Mn 2+ + NO 3 HBrO 3 + Bi HBrO 2 + Bi 2O 3 CrO SO 3 2 Cr 3+ + SO Use the half reaction method to balance the following reactions is basic solution. Fe(OH) 3 + Cr 3+ Fe(OH) 2 + CrO 4 2 MnO 4 + BrO 3 MnO 2 + BrO 4 H 2O 2 + IO 4 IO 2 + O What volume of M Ba(OH) 2 is required to react completely with 3.00 g of sulfur? Ans L H 2(g) + S(s) + 2OH (aq) S 2 (aq) +2H 2O(l)

4 15. Answers Ni(NO 3) 2 + 2NaOH Ni(OH) 2(s) + 2NaNO 3 Ni NO 3 + 2Na + + 2OH Ni(OH) 2(S) + 2Na + + 2NO 3 Ni OH Ni(OH) 2(S) FeCl 3 + 3NaOH Fe(OH) 3(s) + 3NaCl Fe Cl + 3Na + + 3OH Fe(OH) 3(s) + 3Na + + 3Cl Fe OH Fe(OH) 3(s) CuSO 4 + NaCl no reaction AgNO 3 + HCl AgCl(s) + HNO 3 Ag + + NO 3 + H + + Cl AgCl(s) + H + + NO 3 Ag + + Cl AgCl(s) 2Na 3PO 4 + 3Ba(OH) 2 Ba 3(PO 4) 2(s) + 6NaOH 6Na + + 2PO Ba OH Ba 3(PO 4) 2(s) + 6Na + + 6OH 2PO Ba 2+ Ba 3(PO 4) 2(s) 2NH 4Cl + Ba(OH) 2 2NH 4OH + BaCl 2 2NH Cl + Ba OH 2H 2O(l) + 2NH 3(g) + Ba Cl NH OH H 2O(l) + NH 3(g) H 2SO 4 + 2KOH 2H 2O(l) + K 2SO 4 2H + + SO K + + 2OH 2H 2O(l) + 2K + + SO 4 2 H + + OH H 2O(l) Na 2CO 3 + 2HNO 3 2NaNO 3 + H 2CO 3 2Na + + CO H + + 2NO 3 2Na + + 2NO 3 + H 2O(l) + CO 2(g) CO H + H 2O(l) + CO 2(g) 3CaCl 2 + 2K 3PO 4 6KCl + Ca 3(PO 4) 2(s) 3Ca Cl + 6K + + 2PO 4 3 6K + + 6Cl + Ca 3(PO 4) 2(s) 3Ca PO 4 3 Ca 3(PO 4) 2(s) K 2S + 2HCl 2KCl + H 2S(g) 2K + + S 2 + 2H + + 2Cl 2K + + 2Cl +H 2S(g) S 2 + 2H + H 2S(g) 21. Answers HNO 3 + NaOH NaNO 3 + H 2O H + + NO 3 + Na + + OH Na + + NO 3 + H 2O H + + OH H 2O 2HNO 3 + Ba(OH) 2 Ba(NO 3) 2 + 2H 2O 2H + + 2NO 3 + Ba OH Ba NO 3 + 2H 2O H + + OH H 2O 3HNO 3 + Al(OH) 3 Al(NO 3) 3 + 3H 2O 3H + + 3NO 3 + Al 3+ +3OH Al NO 3 + 3H 2O H + + OH H 2O

5 2HF + Mg(OH) 2 MgF 2 + 2H 2O 2H + + 2F + Mg OH Mg F + 2H 2O H + + OH H 2O H 2SO 4 + 2KOH K 2SO 4 + 2H 2O 2H + + SO K + + 2OH 2K + + SO H 2O H + + OH H 2O H 2SO 4 + Mg(OH) 2 MgSO 4 + 2H 2O 2H + + SO Mg OH Mg 2+ + SO H 2O H + + OH H 2O 3H 2SO 4 + 2Al(OH) 3 Al 2(SO 4) 3 + 6H 2O 6H + + 3SO Al OH 2Al SO H 2O H + + OH H 2O H 3PO 4 + 3NaOH Na 3PO 4 + 3H 2O 3H + + PO Na + + 3OH 3Na + + PO H 2O H + + OH H 2O 2H 3PO 4 + 3Ca(OH) 2 Ca 3(PO 4) 2 + 6H 2O 6H + + 2PO Ca OH Ca 3(PO 4) 2(s) + 6H 2O 6H + + 2PO Ca OH Ca 3(PO 4) 2(s) + 6H 2O H 3PO 4 + Al(OH) 3 AlPO 4 + 3H 2O 3H + + PO Al OH AlPO 4(s) + 3H 2O 3H + + PO Al OH AlPO 4(s) + 3H 2O 30. Answers Cu(OH) 2 + 2HNO 3 Cu(NO 3) 2 + 2H 2O nonredox Fe 2O 3 + 3CO 2Fe + 3CO 2 Fe is reduced, C is oxidized Sr(NO 3) 2 + H 2SO 4 SrSO 4 + 2HNO 3 nonredox Zn + 10H + + 2NO 3 4Zn 2+ + N 2O + 5H 2O Zn is oxidized, N is reduced Cl 2 + 2NaI I 2 + 2NaCl I is oxidized, Cl 2 is reduced PbS + 4H 2O 2 PbSO 4 + 4H 2O S is oxidized, O is reduced

6 31. Answers 3Ag + NO 3 + 4H + 3Ag + + NO +2H 2O 8Ni 2+ + IO 4 + 8H + 8Ni 3+ + I 4H 2O P Cl + 12H + 4PH 3 + 6Cl 2 2MnO 4 + 5NO 2 + 6H + 2Mn NO 3 + 3H 2O 3HBrO 3 + 2Bi 3HBrO 2 + Bi 2O 3 2CrO SO H + 2Cr SO H 2O 32. Answers 3Fe(OH) 3 + Cr 3+ 5OH 3Fe(OH) 2 + CrO H 2O 2MnO 4 + 3BrO 3 + H 2O 2MnO 2 + 3BrO 4 + 2OH 2H 2O 2 + IO 4 IO 2 + 2O 2 + 2H 2O