chemical equillib

Which of the following would increase the equilibrium constant for the following reaction? 2H2(g) + O2(g) 2H2O(g) ΔH˚ = -484kJ Increase in [H2] Decrease in [O2] Increase in [H2O] Increase in pressure Decrease in temperature

A change in temperature is the only thing that can change the value of the equilibrium constant. With a negative enthalpy change this reaction is exothermic and releases heat (heat is a product). A decrease in temperature will result in a shift to the right according to Le Chatelier's principle resulting in an increase in the value of the equilibrium constant.

For which of the following reactions is Kp = Kc? 2NH3(g) N2(g) + 3H2(g) N2O4(g) 2NO2(g) 2NO(g) N2(g) + O2(g) 2H2(g) + O2(g) 2H2O(g) CaCO3(s) CaO(s) + O2(g

For Kp and Kc to be equal the number of moles of gaseous reactants must be the same as the number of moles of gaseous products. Among the answer choices that is only true for the following reaction: 2NO(g) N2(g) + O2(g)

For an elementary reaction the forward and reverse rate constants are equal to 3.0x10-4s-1 and 2.0x10-6s-1. What is the equilibrium constant for this reaction? 1.5x102 6.7x102 6.7x10-2 1.5x10-2 6.0x102

For an elementary reaction Kc = kf/kr Kc = (3.0x10-4s-1)/( 2.0x10-6s-1) Kc = 1.5x102

Which of the following is false for the following reaction at equilibrium? A(aq) ® B(aq) Kc = 2.8x10-5 [A] > [B] kforward = kreverse Δ[reactants]/Δt = 0 Δ[products]/Δt = 0 [B]/[A] = 2.8x10-5

it is the forward and reverse rates that are equal at equilibrium, not the forward and reverse rate constants (kforward = kreverse is false). At equilibrium the forward rate is equal to the reverse rate so that the overall reactant and product concentrations are not changing. As Kc is much smaller than 1 [A] > [B] at equilibrium. And the ratio of [B]/[A] = 2.8x10-5 as this is the equilibrium constant expression.

A rigid container was charged with 4atm of both A2 and B2. What is the equilibrium partial pressure of AB? A2(g) + B2(g) 2AB(g) Kc = 4.0x10-8 2x10-4M 4x10-4M 8x10-4M 1.6x10-7M 1.6x10-8M

option 3

Which of the following is/are always true about a reaction at equilibrium? I. [reactants] = [products] II. forward rate = reverse rate III. Δ[reactants]/Δt = 0 II only I and II I and III II and III I, II, and III

option 4 For a reaction at equilibrium the forward rate equals the reverse rate (II is true) so that the concentrations of all reactants and products are not changing (III is true). But the concentration of the reactants need not equal the concentration of the products (I is false). Some reactions have significantly more products present at equilibrium (K>>1), some have significantly more reactants present at equilibrium (K<<1), and some have similar concentrations of reactants and products present at equilibrium (K ~ 1).

A rigid container was charged with 4atm N2O4. At equilibrium the partial pressure of N2O4 is 1atm. What is the equilibrium partial pressure of NO2? N2O4(g) 2NO2(g) 2atm 3atm 4atm 5atm 6atm

the ICE table for the reaction is shown below: The equilibrium partial pressure of N2O4 is 1atm and therefore 4 - x = 1atm x = 3atm The equilibrium partial pressure of NO2 is 2x according to the ICE table. 2x = (2)(3atm) = 6atm