Chapter 15
Chapter 15 cont
Acids and Bases
Acids and Bases Cont.
Acids and Bases Equilibrium
100
If K is greater than Q what way does the reaction proceed?
Forward
100
How does changing the pressure affect equilibrium?
(inc pressure and dec pressure)
inc --> towards less moles of gas
dec --> towards more moles of gas
100
What are the strong acids?
HCl, HBr, HI, HNO3, H2SO4, HClO4
100
Which of the following acids ionizes to give the strongest conjugate base?
(a) HCl
(b) HNO3
(c) HClO4
(d) H2SO4
(e) HCN
HCN
100
What is the percent ionization of an 1.2 M HF solution? Ka = 6.6 x 10-4
2.4 %
200
An exothermic reaction is allowed to reach equilibrium. What direction will the reaction proceed if it is heated?
2H2(g)+O2(g)⇌2H2O(g)
Favors the reverse reaction
200
Consider the equilibrium system:
2ICl(s) I2(s) + Cl2(g)
Which of the following changes will increase the total amount of of Cl2 that can be produced?
(a) removing some of the I2(s)
(b) adding more ICl(s)
(c) removing the Cl2 as it is formed
(d) decreasing the volume of the container
(e) all of the above
C
200
Which one of the following is a conjugate acid–base pair?
a. NH3 and NH4+
b. H2O and O2–
c. H3O+ and OH–
d. NaF and F–
e. NH2-and NH4+
NH3 and NH4+
200
The pOH of a solution of NaOH is 11.30. What is the [H+] for this solution?
2.0e-3
200
What is the pH of a solution labeled 0.050 M HClO? Ka = 2.9 x 10-8
4.4
300
H2(g)+I2(g)⇌2HI(g)
What happens when H2 is added?
reaction favors the forward reaction
300
Consider the reaction:
N2(g) + O2(g) 2NO(g)
Kc = 0.10 at 2000oC
Starting with initial concentrations of 0.040 mol/L of N2 and 0.040 mol/L of O2, calculate the equilibrium concentration of NO in mol/L
0.011 M
300
Which of the following compounds cannot be a Brønsted–Lowry base?
(a) OH-
(b) NO3-
(c) NH3
(d) HPO42-
(e) NH4+
(e) NH4+
300
If Kw is 2.9 x 10-15 at 10oC, what is the pH of pure water at 10oC?
7.27
300
What is the concentration of a sodium acetate solution if the pH of the solution is 9.19?
Ka of acetic acid = 1.8 x 10-5
0.43 M
400
3H2(g)+N2(g)⇌2NH3(g)
what happens when the volume is decreased?
Favors the forward reaction
400
A mixture consisting initially of 3.00 moles NH3, 2.00 moles of N2, and 5.00 moles of H2, in a 5.00 L container was heated to 900 K, and allowed to reach equilibrium. What direction will the reaction proceed?
2 NH3(g) 
N2(g) + 3 H2(g) Kc = 0.0076 @ 900K
left (reverse)
400
HA Ka = 4.5 x 10-4
HB Ka = 6.7 x 10-10
HC Ka = 8.3 x 10-4
HD Ka = 6.0 x 10-6
What is the strongest acid?
HA
400
Which of the following salts forms a solution with a pH of 7?
(a) NH4Br
(b) NaCN
(c) KNO3
(d) Na2CO3
(e) LiH2PO4
6.3e-10
400
A 0.10 M solution of a weak acid, HX, is 0.059% ionized. Evaluate Ka for the acid.
3.5e-8
500
COBr2(g)⇌CO(g)+Br2(g)
What happens to the reaction when inert argon gas, Ar(g), is added?
nothing --> still at equilibrium
500
At 445oC, Kc for the following reaction is 0.020.
2HI(g) H2(g) + I2(g)
A mixture of H2, I2, and HI in a vessel at 445oC has the following concentrations: [HI] = 2.0 M, [H2] = 0.50 M and [I2] = 0.10 M
Which direction will the reaction proceed?
forward (right)
500
Aqueous solutions of ____ are basic.
(a) NaF
(b) NaCl
(c) NaBr
(d) NH4Cl
(e) K2SO4
NaF
500
The [H3O+] in a 0.050 M solution of Ba(OH)2 is:
1.0e-13
500
What is the pH of a 0.20 M solution of ammonia? The Kb value for ammonia is 1.8 × 10–5
11.28