CHM 2046 EXAM 1 FORM CODE A 1/31/2008
Please bubble in your name, UFID #, and form code on the answer sheet using a #2 pencil.
The form code for this exam is form code A.
1. Which best describes NH ? 3
(a) A polyprotic base
(b) A strong electrolyte
(c) A weak base
(d) An amphiprotic species
(e) The conjugate acid of a weak base
2. Consider a solution of 0.0070 M Ca(OH) ; what2is the pH of this solution?
(a) 0.602 (b) 12.8 (c) 1.1 (d) 12.1 (e) -2.15
3. Which of the following is not a strong acid?
(a) Citric acid (b) HI (c) HBr (d) Nitric acid (e) Perchloric acid
4. A compound, AB, dissociates in water according to the formula
AB (aq) A (aq) + B(aq) K c 16
+ - -
At equilibrium [AB] = 0.25M and [A ] = [B] = 2.0 M. At this point, 2.0 M [B] is added to the reaction.
What will be the concentration of AB when the system reaches equilibrium again?
(a) 0.18 M (b) 0.07 M (c) 0.43 M (d) 0.60 M (e) 0.45 M
5. Without doing any explicit calculations, rank the following solutions in terms of DECREASING pH
0.1 M HI, 0.1 M HF, 0.01M HF, 0.1 M NH , 3 0.01 M KOH, 0.1 M KOH, 0.1 M NaBr
Highest pH Lowest pH
(a) 0.1 M HI, 0.01 M HF, 0.1 M HF, 0.1 M NaBr, 0.1 M NH , 0.01 M KOH, 0.1 M KOH
(b) 0.1 M HF, 0.01 M HF, 0.1 M HI, 0.1 M NaBr, 0.1 M NH , 0.01 M KOH, 0.3 M KOH
(c) 0.01 M KOH, 0.1 M KOH, 0.1 M NH , 0.1 M NaBr3 0.1 M HF, 0.01M HF, 0.1 M HI
(d) 0.1 M NH , 3.1 M KOH, 0.01 M KOH, 0.1 M HI, 0.01M HF, 0.1 M HF, 0.1 M NaBr
(e) 0.1 M KOH, 0.01 M KOH, 0.1 M NH , 0.1 M NaBr3 0.01 M HF, 0.1M HF, 0.1 M HI
6. Which of the following is NOT a Bronsted base?
(a) NH 3 (b) F- (c) H 2 (d) CH C3O - (e) They are all Bronsted bases
7. An aqueous solution is found to have a negative pH. Which of the following may apply to this
solution? + -2 - -15 +
(a) [H 3 ] = 1.0×10 M (b) [OH] = 1.0×10 M (c) [H3O ] = 1 M
(d) It is not possible to have a negative pH (e) [OH] = 10 M
8. Given that the following reaction is at equilibrium,
2N (2) + 4H O(2) 4NO(g) + 4H (g)2
what will be the effect of increasing the pressure?
(a) the product concentrations will increase (b) the product concentrations will decrease
(c) no effect (d) the reactant concentrations will decrease (e) both A and D
9. At 100 ºC, K =c7.62×10 for the reaction 2NOBr(g) 2NO(g) + Br (g) 2
0.0040 moles of NOBr(g), 0.0030 moles of NO(g), and 0.0030 moles of Br (g) are intr2duced into a 1.0-L
container. Calculate the reaction quotient. Which way will the reaction proceed?
(a) Q= 6.75×10 , Right to Left
(b) Q= 5.62×10 , Right to Left
(c) Q= 2.25×10 , Right to Left
(d) Q=5.93×10 , Left to Right
(e) Q=1.69×10 , Right to Left
10. For the following reaction K = c.93 at 1200 K. CO (g) + 2H (g2 CH (4) + H O 2g)
Given R = 0.082 L Atm mol K , calculate K for thispreaction at 1200 K.
(a) 4.04×10 -4 (b) 4.00×10 -2 (c) 1.05×10 -4 (d) 2.12×10 -4 (e) 1.54×10 -12
11. What is the [H O3] of a solution that has a pH of 8.50?
(a) 3.2×10 8 (b) 3.2×10 6 (c) 0.93 (d) 1.0×10 7 (e) 3.2×10 -9
12. Consider the following reaction for which ΔH 0 < 0: A (s) + B (g) C (s)
Which of the following statements is correct? I Adding A shifts the reaction right.
II Increasing the volume shifts the reaction left.
III Decreasing the temperature shifts the reaction right.
(a) I, II, III (b