Mastering Chemistry Through Understanding of Stuff

1. Which substance below when mixed with HNO3 would lead to the formation of a salt and H2O? A. B. C. D. 3. KOH (aq) Ag (s) H3PO4 (aq) Ca (s) Which compound(s) is a strong acid? I. Chloric acid, HClO3 A. B. C. D. 4. I only II only Both I and II Neither I or II What term best describes acetic acid, CH3COOH, in aqueous solution? A. B. C. D. 5. II. Sulfurous acid, H2SO3 Weak polyprotic acid Weak monoprotic acid Strong polyprotic acid Strong monoprotic acid Which compound below is a weak electrolyte and weak base in aqueous solution? A. B. C. D. Cu(OH) 2 NaOH CH3OH NH3 6. The conductivity of a solution is directly proportional to the concentration of dissolved ions. When 1.0 mole of each of the following compounds is dissolved into 10.0 L of water, which compound leads to a solution with the least conductivity? A. B. C. D. 7. Which statement below is true? A. B. C. D. 8. NO3− Na+ PO43− Ca 2+ What is the molarity of potassium ions in a solution prepared by diluting 125 mL of 0.250 M K3PO4 to a total volume of 1.50 L? A. B. C. D. 10. All water soluble compounds are strong electrolytes All ionic compounds are water soluble All strong electrolytes are ionic compounds All water soluble ionic compounds are strong electrolytes 30.0 mL of 0.10 M Ca(NO3)2 and 15.0 mL of 0.20 M Na3PO4 solutions are mixed. After the reaction is complete, which of these ions has the lowest concentration in the final solution? A. B. C. D. 9. KF NH3 Li2CO3 NaNO3 0.0625 M 0.0781 M 0.0208 M 0.0312 M What is the oxidation number of C in formaldehyde, CH2O? A.  B. 0 C. +2 D. +1 11. A 12.50 g sample of a water-soluble barium salt is treated with an excess of sodium sulfate to precipitate 11.17 g of BaSO4 (MM=233.4 g/mol). Which barium salt is it? A. B. C. D. 12. Ba(NO3)2 (MM=261.3 g/mol) Ba(C2H3O2)2 (MM=212.3 g/mol) BaI2 (MM=391.1 g/mol) Ba(ClO3)2 (MM=300.6 g/mol) Which metal(s) will dissolve in a solution of hydrochloric acid, HCl? I. Gold A. B. C. D. 13. Only I Only II Both I and II Neither I or II When Cu(NO3)2 is mixed with Ni(s) in water, what type of reaction takes place? A. B. C. D. 14. Oxidation-reduction Metathesis Combination No reaction occurs Which compound(s) is soluble in water? I. HgBr2 A. B. C. D. 15. II. Aluminum II. Hg2SO4 III. Hg2(C2H3O2)2 I and III I and II II and III I, II, and III 5.50 g of glucose, C6H12O6 is added to an empty volumetric flask, which is then then filled water until the solution obtains a volume of 250.0 mL. What is the concentration of glucose in the solution in units of molarity? A. B. C. D. 2.2 M 3.96 M 0.0455 M 0.122 M 16. A 50.0 mL sample of 0.25 M silver nitrate, AgNO3, is reacted with a 4.78 g sample of calcium chloride, CaCl2 (MM=110.98 g/mol). Which of the following statements is true? A. B. C. D. 17. When aqueous solutions of lead chlorate, Pb(ClO3)2, and potassium sulfate, K2SO4, are mixed which ions are termed the spectator ions? A. B. C. D. 18. 10 mL graduated cylinder 10 mL volumetric pipet 10 mL beaker 25 mL beaker Potassium hydrogen phthalate (abbreviated KHP), KHC8H4O4, is a solid monoprotic acid readily available in pure form, hence it is useful in titrations to determine the concentration of a stock solution of base. If 25.50 mL of a stock solution of potassium hydroxide, KOH is required to fully titrate 0.6575 g of KHC8H4O4 (MM=204.22 g/mol), what is the molarity of KOH in the stock solution? A. B. C. D. 20. Lead and sulfate ions Potassium and chlorate ions Only lead ion Sulfate and chlorate ions What piece of lab equipment is the best choice to deliver a 10.00 mL sample of acid from a stock container to a flask for a titration? A. B. C. D. 19. Silver nitrate is the limitaing reactant and calcium nitrate precipitates Silver nitrate is the limiting reactant and silver chloride precipitates Calcium chloride is the limiting reactant and calcium nitrate precipitates Calcium chloride is the limiting reactant and silver chloride precipitates 0.7920 M 0.08211 M 0.1263 M 0.02578 M Which method(s) can be used to determine the concentration of HCl in a 10.00 mL aqueous solution of HCl? I. Determing the volume of 0.100 M NaOH required to titrate the solution II. Adding an excess of AgNO3 and determing the mass of dried precipitate. A. B. C. D. I only II only Both I and II Neither I or II 21. A 150-pound athlete running a 26.2 mile marathon will burn about 2.0x103 kcal during the race. How much energy is this in kJ? A. B. C. D. 22. 0.48 kJ 8.4 kJ 8400 kJ 480 kJ Which reaction(s) below is endothermic? I. Freezing of water A. B. C. D. 24. II. Boiling of water Only I Only II Both I and II Neither I or II When potassium hydroxide dissolves in water, does the water temperature increase or decrease and why? KOH (s) → K+ (aq) + OH− (aq) A. B. C. D. 25. ΔHº = −57.6 kJ Temperature increases because the reaction absorbs heat Temperature decreases because the reaction releases heat Temperature increases because the reaction releases heat Temperature decreases because the reaction absorbs heat When 2.50 moles of ammonium nitrate dissolves in water, how much heat is either released or absorbed by the reaction. NH4NO3 (s) → NH4+ (aq) + NO3− (aq) A. B. C. D. 10.3 kJ is released by reaction 10.3 kJ is absorbed by reaction 64.2 kJ is released by reaction 64.2 kJ is absorbed by reaction ΔHº = +25.7 kJ 26. If 3.50 grams of NH4NO3 (MM=80.05 g/mol) is added to and dissolves in 125 g of water inside a coffee cup calorimeter initially at 25.0 ºC, what is the final temperature of the solution if the enthalpy of solution of NH4NO3 is +25.7 kJ/mol? The specific heat of the solution is 4.184 J/gK. Assume the calorimeter materials have a neglible heat capacity. A. B. C. D. 27. If a 25.00 g piece of copper (Cs=0.385 J/gK) at 115.0 ºC is added to 50.00 g of water (Cs=4.184 J/gK) at 25.00 ºC, what is the final temperature once the object and water thermally equilibrate, assuming no heat is lost to their surroundings. A. B. C. D. 28. 72.8 ºC 27.1 ºC 22.9 ºC 16.5 ºC 45.7 ºC 20.7 ºC 31.8 ºC 29.0 ºC When 1.00 g of oxalic acid, H2C2O4, is burned in a calorimeter with a total heat capacity including water is 8.75 kJ.K-1 the temperature increases from 25.000 to 25.312ºC. Calculate the enthalpy of combustion of oxalic acid in kJ/mol. A. B. C. D. 354 kJ/mol 246 kJ/mol 298 kJ/mol 273 kJ/mol 30. Consider these reactions, where M represents a generic metal. 2 M (s) + 6 HCl (aq) → 2 MCl3 (aq) + 3 H2 (g) HCl (g) → HCl (aq) H2 (g) + Cl2 (g) → 2 HCl (g) MCl3 (s) → MCl3 (aq) ΔHº = −830.0 kJ ΔHº = −74.8 kJ ΔHº = −1845.0 kJ ΔHº = −330.0 kJ Use the information above to determine the enthalpy of reaction of the following reaction in kJ: 2 M (s) + 3 Cl2 (g) → 2 MCl3 (s) A. B. C. D. 31. +3079.8 kJ −6153.8 kJ −3079.8 kJ +6153.8 kJ Given the below reaction and its enthalpy of reaction, use any necessary information from Appendix C (attached) to solve for the enthalpy of formation of octane in kJ/mol? C8H18 (l) + 25/2 O2 (g) → 8 CO2 (g) + 9 H2O (l) ΔHº = −5471 kJ A. B. C. D. 32. −249 kJ/mol +5470 kJ/mol +2901 kJ/mol −4792 kJ/mol Using values as needed from Appendix C, determine the enthalpy of reaction (ΔHº) for the reaction: CH4 (g) + 2 Cl2 (g) → CCl4 (g) + 2 H2 (g) A. B. C. D. −181.5 kJ −64.5 kJ −214.1 kJ −31.9 kJ 33. Considering the enthalpy of the below reaction using Appendix C (attached), which statement can you conclude about the bond strengths of the molecules in the reaction? CH4 (g) + 2 Cl2 (g) → CCl4 (g) + 2 H2 (g) A. Because the reaction is exothermic, the bonds in the reactants are stronger (more stable) than those in the products B. Because the reaction is exothermic, the bonds in the products are stronger (more stable) than those in the reactants C. Because the reaction is endothermic, the bonds in the reactants are stronger (more stable) than those in the products D. Because the reaction is endothermic, the bonds in the products are stronger (more stable) than those in the reactants 34. The fuel value of dietary carbohydrates, protein, and fats are about 3.7, 3.9, and 8.7 kcal/g, respectively. Would eating 25 grams of carbohydrate, protein, or fat allow you to expend the most energy? A. B. C. D. Carbohydrate Protein Fat All three would allow an equal amount of energy to be expended