NEET Equilibrium — Set 13

Question 1

For $ \ce{A2(g) + B2(g) <=> 2AB(g)} $, $ K_p = 9 $ at 600 K. If initial pressures are $ P_{\ce{A2}} = 1 \, \text{atm} $, $ P_{\ce{B2}} = 1 \, \text{atm} $, what is $ P_{\ce{AB}} $ at equilibrium?

Accepted Answer

Let $ 2x $ be $ P_{\ce{AB}} $, $ P_{\ce{A2}} = 1 - x $, $ P_{\ce{B2}} = 1 - x $, total pressure = $ (1 - x) + (1 - x) + 2x = 2 $. $ K_p = \frac{(P_{\ce{AB}})^2}{P_{\ce{A2}} P_{\ce{B2}}} = \frac{(2x)^2}{(1 - x)^2} = 9 $, $ \frac{4x^2}{(1 - x)^2} = 9 $, $ \frac{2x}{1 - x} = 3 $, $ 2x = 3 - 3x $, $ 5x = 3 $, $ x = 0.6 $, $ P_{\ce{AB}} = 2 \times 0.6 = 1.2 \, \text{atm} $.

Question 2

For the equilibrium $ \ce{X2(g) <=> 2X(g)} $, if the initial pressure of $ \ce{X2} $ is 2 atm and at equilibrium the total pressure is 3 atm, what is $ K_p $?

Accepted Answer

Let the pressure of $ \ce{X} $ at equilibrium be $ 2p $, $ \ce{X2} = 2 - p $, total pressure = $ (2 - p) + 2p = 2 + p = 3 $, $ p = 1 $. $ P_{\ce{X2}} = 1 \, \text{atm} $, $ P_{\ce{X}} = 2 \, \text{atm} $. $ K_p = \frac{(P_{\ce{X}})^2}{P_{\ce{X2}}} = \frac{(2)^2}{1} = 4 $.

Question 3

For $ \ce{COCl2(g) <=> CO(g) + Cl2(g)} $, $ K_c = 0.16 $ at 700 K. If 0.2 mol $ \ce{COCl2} $ and 0.1 mol $ \ce{CO} $ are in a 1 L vessel, what is $ [\ce{Cl2}] $ at equilibrium?

Accepted Answer

Initial: $ [\ce{COCl2}] = 0.2 \, \text{M} $, $ [\ce{CO}] = 0.1 \, \text{M} $, $ [\ce{Cl2}] = 0 $. Let $ x = [\ce{Cl2}] $, $ [\ce{COCl2}] = 0.2 - x $, $ [\ce{CO}] = 0.1 + x $. $ K_c = \frac{[\ce{CO}][\ce{Cl2}]}{[\ce{COCl2}]} = \frac{(0.1 + x)x}{0.2 - x} = 0.16 $, $ 0.1x + x^2 = 0.032 - 0.16x $, $ x^2 + 0.26x - 0.032 = 0 $, $ x \approx 0.11 \, \text{M} $.

NEET Chemistry: Equilibrium — Practice Set 13

Q1. For \( \ce{A2(g) + B2(g) <=> 2AB(g)} \), \( K_p = 9 \) at 600 K. If initial pressures are \( P_{\ce{A2}} = 1 \, \text{atm} \), \( P_{\ce{B2}} = 1 \, \text{atm} \), what is \( P_{\ce{AB}} \) at equilibrium?

Q2. For the equilibrium \( \ce{X2(g) <=> 2X(g)} \), if the initial pressure of \( \ce{X2} \) is 2 atm and at equilibrium the total pressure is 3 atm, what is \( K_p \)?

Q3. For \( \ce{COCl2(g) <=> CO(g) + Cl2(g)} \), \( K_c = 0.16 \) at 700 K. If 0.2 mol \( \ce{COCl2} \) and 0.1 mol \( \ce{CO} \) are in a 1 L vessel, what is \( [\ce{Cl2}] \) at equilibrium?

Q4. A weak base \( \ce{BOH} \) has a \( K_b = 4.0 \times 10^{-6} \). What is the pH of a 0.01 M solution of \( \ce{BOH} \)?

Q5. What is the conjugate acid of \( \ce{NH3} \)?

Q6. The \( K_a \) of a weak acid \( \ce{HX} \) is \( 2.5 \times 10^{-5} \). What is its \( \text{p}K_a \)?

Q7. The \( K_b \) of a weak base \( \ce{B} \) is \( 3.2 \times 10^{-6} \). What is its \( \text{p}K_b \)?

Q8. For the reaction \( \ce{A(g) + 2B(g) <=> 3C(g)} \), \( K_c = 27 \) at 400 K. If 1 mole of \( \ce{A} \) and 3 moles of \( \ce{B} \) are placed in a 1 L vessel, what is \( [\ce{C}] \) at equilibrium?

Q9. The solubility of \( \ce{Ag2SO4} \) in 0.1 M \( \ce{Na2SO4} \) is \( 5.0 \times 10^{-5} \, \text{M} \). What is its \( K_{sp} \)?

Q10. The \( K_{sp} \) of \( \ce{PbCl2} \) is \( 1.7 \times 10^{-5} \). What is the solubility of \( \ce{PbCl2} \) in a 0.1 M \( \ce{KCl} \) solution?