1. (4 pts) Name the following compounds: Al 2 (SO 4 ) 3 N 2 O 3 2. (4 pts) Give the chemical formulas for the following compounds: chromium (III) carbonate magnesium phosphate 3. (16 pts) Circle the formula that best fits each of the following descriptions: a) most likely to gain two electrons Br O Al Mg b) greatest tendency to form a negative ion Na Li S Mg c) a non-metal Sr S Al K d) soluble in water PbSO 4 Na 2 CO 3 Mg(OH) 2 BaSO 4 e) a covalent compound NH 3 NH 4 Cl KBr KClO 4 f) an ionic compound H 2 O NO LiF CH 4 g) larger mass neutron electron h) greatest mass percent of phosphourous PF 3 P 4 O 10 P 4 O 6 4. (8 pts) Draw the Lewis structure for for each of the following compounds. Show the lone pairs of electrons. a) SO 2 Lewis structures will not be on the exam this year. b) OCl 5. (4 pts) Write the balanced equation for the complete combustion of fructose, C 6 H 12 O 6. Use integer coefficients. 1
6. (6 pts) Consider the following reaction at equilibrium:. N 2 O 4 (g) 2 NO 2 (g) The value of K is 0.90 at 120 o C and 3.2 at 150 o C. Predict how the equilibrium will shift by the following changes. Circle the correct answer. a) The temperature is decreased. left right no shift b) An inert gas, argon, is added. left right no shift c) The volume is decreased. left right no shift 7. (8 pts) A scuba diver s tank contains 0.30 kg of oxygen (O 2 ) compressed into a volume of 2.32 L. a) Use the ideal gas law to estimate the gas pressure inside the tank at 5 o C. b) What volume would this oxygen occupy at 30 o C and a pressure of 1.0 atm? 8. (9 pts) Consider three identical flasks filled with different gases. Flask A: N 2 at 760 torr and 0 o C Flask B: O 2 at 250 torr and 0 o C Flask C: Ne at 100 torr and 0 o C Circle the correct answer for each of the following questions. a) In which flask will the molecules have the greatest average kinetic energy? Flask A Flask B Flask C All are the same b) In which flask do the molecules have the greatest average velocity? Flask A Flask B Flask C All are the same c) In which flask is the number of collisions per second between molecules the greatest? Flask A Flask B Flask C All are the same 2
9. (8 pts) What mass of AlBr 3 is formed by the reaction of 10.0 g of Al and 10.0 g Br 2? Al reacts with Br 2 according to the following equation. The reaction goes to completion. Show your work. Circle the answer. 2 Al + 3 Br 2 > 2 AlBr 3 a) 10.0 g b) 11.1 g c) 20.0 g d) 98.8 g e) 110. g 10. (10 pts) An excess of solid NH 4 Cl is added to a container filled with 1.5 atm of ammonia gas at 340 o C. Calculate the pressures of HCl and NH 3 at equilibrium. HCl (g) + NH 3 (g) NH 4 Cl (s) K = 4.0 at 340 o C 11. (4 pts) 40 ml of 2.0 M (NH 4 ) 3 PO 4 solution is diluted by adding 60 ml of water. Calculate the concentration of NH 4 + in the final solution. 12. (4 pts) For a 0.1 M solution of each of the following salts indicate if the solution will be acidic, basic or neutral. a) KNO 3 b) NaF c) NH 4 Br d) NaHCO 3 3
13. (12 pts) Circle the correct answer for each of the following questions. a) Which is the strongest acid? H 2 S H 2 O H 2 CO 3 b) Which is the strongest base? ClO H 2 O C 5 H 5 N c) Which salt, when dissolved in water, will produce the most basic solution? KCl KCN KNO 2 KNO 3 d) Which of the following 0.1 M solutions will have the lowest ph? NaNO 3 NaOH HF KF 14. (10 pts) A strong acid, HA, is titrated with the strong base, Ba(OH) 2. Determine the ph of the solution when 30 ml of 1.0 M Ba(OH) 2 has been added to 40 ml of 1.0 M HA? Show your work. Circle the answer. a) ph < 7 b) ph = pk a c) ph > 7 d) ph = 7 15. (10 pts) For the buffer solution, made by mixing 50 ml of 0.5 M HF and 50 ml of 0.6 M NaF, calculate the ph after 10 ml of 0.1 M NaOH has been added. Show your work. Circle the answer. a) ph = 3.26 b) ph = 3.18 c) ph = 3.29 d) ph = 7.0 4
16. (8 pts) If 50 ml of 2.0 x 10 4 M Ca(NO 3 ) 2 is mixed with 50 ml of 2.0 x 10 4 M NaF, will the precipitate CaF 2 (s) be formed? You must show your work to determine if a precipitate forms. CaF 2 (s) Ca 2+ (aq) + 2 F (aq) K sp = 1 x 10 11 17. Consider the following reaction. HPO 4 2 (aq) + HCO 3 (aq) PO 4 3 (aq) + H 2 CO 3 (aq) a) (4 pts) Using the data in the Table of Acid Ionization Constants determine the equilibrium constant, K, for this reaction. b) (2 pts) Identify the stronger acid in this reaction. c) (2 pts) Identify the stronger base in this reaction. 18. Barium sulfate reacts with potassium phosphate to produce barium phosphate and potassium sulfate. a) (6 pts) Write the balanced molecular equation for this reaction. b) (4 pts) Write the net ionic equation for this reaction. 5
19. (8 pts) Calculate the ph of a 0.16 M NaCH 3 COO solution. 20. (10 pts) Calculate the volume of 1.5 x 10 2 M NaOH that must be added to 500.0 ml of 0.200 M HCl to give a solution that has ph = 2.15. 6