Practice Exam 2 CHEM 1411 1. Which of the following is a weak electrolyte? a) BaCl2 b) NH4Cl c) CH3COOH d) HCl 2. A strong electrolyte in solution mainly consists of a) Ions b) molecules c) ions and molecules d) atoms 3. Which of the following is a strong base? a) NaOH b) Al(OH)3 c) NH4OH d) NH3 4. Write the molecular, ionic, and net ionic equations for the reaction of ammonium chloride and silver nitrate. 5. Write the net ionic equation for the following reaction: HCl+ KOH H2O + KCl 6. When lead II nitrate and sodium chloride react, what are the spectator ions? For #7-10, identify the following reaction types as combination, decomposition, combustion, or displacement. 7. CH4 + O2 CO2+ H2O 8. CaO + CO2 CaCO3 9. PbCO3 PbO + CO2 10. AgNO3 + HF AgF + HNO3 11. What is the concentration of HCl if 35 ml of 0.6 M KOH were used to titrate 100 ml of acid? 12. What is the concentration of a solution produced by dissolving 27 g NaOH in enough water to make 500 mL? 13. How many grams of CH3OH are required to produce 230 mL of a 0.275M solution? 14. There are ____ moles in a 150mL of a 0.25M solution. 15. What is the oxidation number of C in K2CO3? 16. What is the oxidation number of N in AgNO3? Answer questions 17-19 using the following equation: H+(aq) + 6Cl–(aq) + Sn(s) + 4NO3–(aq) SnCl6 2-(aq) + 4NO2(g) + 4H2O 17. Is this a redox reaction? Why? 18. What species was reduced? Oxidized? 19. What is the reducing agent? 20. Which of the following is the strongest reducing agent? a) H b) Mg c) Ca d) Fe 21. Oxidation is _____ of electrons while reduction is _____ of electrons. a) Loss, gain b) Gain, loss c) Loss, loss d) Gain, gain 22. Gay Lussac’ s Law describes the relationship between ______ as being _______ proportional. a) P/T, directly b) P/T, indirectly c) P/V, directly d) V/T, directly 23. What is the density of SO2 gas held at 870 mmHg of pressure at 30 degrees Celsius? 24. What is the volume of 2.2 mols of N2 gas at STP? 25. What is the initial temperature of a 2L sample of unknown gas if it reaches a volume of 2.3L when heated to 23 C? 26. 920 torrs= _______atm? 27. A + ΔH value is considered to be a) Endothermic b) exothermic c) redoxive d) caloric 28. A 12.0-g sample of metal at 18.0°C is added to 50.0 g of H2O at 10.0°C. The temperature rises to 14.5°C. Assuming that the calorimeter is a perfect insulator, what is the specific heat of the metal? [Specific heat of H2O is 4.184 J/(g • °C).] 29. Calculate ∆H for the following reaction using Hess’ Law: Given: H2 + F2 2HF ∆H= -537 kJ 2C + 2H2 C2H4 ∆H=+52 kJ CF4 C + 2F2 ∆H=680 kJ Find ∆H of: C2H4 + 6F2 2CF4 + 4HF 30. What is the ΔH value for the following reaction if 6 moles of HCl were reacted? Zn + 2HCl ZnCl2 + H2 + 76 kJ a) 76 kJ b) -76kJ c) 228 d) -228 e) -152 31. What is the heat released by a substance whose heat capacity is 0.52 J/C when it is cooled from 35C to 25C?