A buffer solution is prepared in which the concentration of NH₃ is 0.30 M and the concentration of  $N{H}_4^{+ }$ is 0.20 M. If the equilibrium constant, K_b for NH₃ equals 1.8×10^–5, then what is the pH of this solution? 
(log 1.8 = 0.25; log 0.67 = –0.176)

1.  9.43
2.  11.72
3.  8.73
4.  9.08

The equilibrium reaction that doesn't have equal values for K_c and K_p is: 

1. \(2NO(g) \rightleftharpoons N_2(g) + O_2(g)\)
2. \(SO_2(g) + NO_2(g) \rightleftharpoons SO_3(g) + NO(g)\)
3. \(H_2(g) + I_2(g) \rightleftharpoons 2HI (g)\)
4. \(2C(s) + O_2(g) \rightleftharpoons 2CO_2(g)\)

Which of the following molecular hydrides acts as a Lewis acid?

1. $N{H}_3$

2. $H_{2}O$

3. $B_2{H}_6$

4. $C{H}_4$

The tendency of BF₃, BCl₃ and BBr₃ to behave as Lewis acid decreases in the sequence:

1. $BC{l}_3>B{F}_3>BB{r}_3$

2. $BB{r}_3>BC{l}_3>B{F}_3$

3. $BB{r}_3>B{F}_3>BC{l}_3$

4. $B{F}_3>BC{l}_3>BB{r}_3$

The ionization constant of ammonium hydroxide is 1.77 x 10^-5 at 298 K. Hydrolysis constant of ammonium Chloride is:

1. 5.65 x 10^-10

2. 6.50 x 10^-12

3. 5.65 x 10^-13

4. 5.65 x 10^-12

What is the [OH^-] in the final solution prepared by mixing 20.0 mL of 0.050 M HCl with 30.0 mL of 0.10 M Ba(OH)₂?

1. 0.10 M

2. 0.40 M

3. 0.0050 M

4. 0.12 M

The dissociation constants for acetic acid and HCN at 25 °C are 1.5 x 10^-5 and 4.5 x 10^-10, respectively. The equilibrium constant for the equilibrium, 
CN^- + CH₃COOH  ⇌  HCN + CH₃COO^- 
would be:
1. $3.0\times {10}^5$
2. $3.0\times {10}^{-5}$
3. $3.0\times {10}^{-4}$
4. $3.0\times {10}^4$

If the concentration of OH ' ions in the reaction 

The dissociation equilibrium of a gas AB₂ can be represented as 
 $2A{B}_2\left(g\right)$ $\leftrightharpoons$ $2AB\left(g\right)$ $+$ $B_2\left(g\right)$ $$
The degree of dissociation is ‘x’ and is small compared to 1. The expression relating the degree of dissociation (x) with equilibrium constant K_P and total pressure p is:
1. (2KP/p)
2. (2Kp /p)^1/3
3. (2KP/p)^1/2
4. (KP/P)