Unit 8 Quiz 4

Consider the reaction. mc019-1.jpg At equilibrium, the concentrations of the different species are as follows. [NH3] = 0.105 M [N2] = 1.1 M [H2] = 1.50 M What is the equilibrium constant for the reaction at this temperature? 0.0030 0.030 34 340

0.0030

Consider the reaction. mc033-1.jpg At equilibrium, the concentrations are as follows. [NOCl] = 1.4 ´ 10-2 M [NO] = 1.2 ´ 10-3 M [Cl2] = 2.2 ´ 10-3 M What is the value of Keq for the reaction expressed in scientific notation? 1.6 ´ 10-5 6.2 ´ 10-4 6.2 ´ 104 1.6 ´ 105

1.6 ´ 10-5

Consider the reaction. mc026-1.jpg At equilibrium at 600 K, the concentrations are as follows. [HF] = 5.82 x 10-2 M [H2] = 8.4 x 10-3 M [F2] = 8.4 x 10-3 M What is the value of Keq for the reaction expressed in scientific notation? 2.1 x 10-2 2.1 x 102 1.2 x 103 1.2 x 10-3

2.1 x 10-2

Consider the reaction below. mc009-1.jpg If the reaction is at dynamic equilibrium at 500 K, which statement applies to the given chemical system? The forward and reverse reactions no longer occur. The rates of the forward and reverse reactions are unequal. The concentrations of the products and reactants do not change. The forward reaction stops at 500 K.

The concentrations of the products and reactants do not change.

Consider the equilibrium system below. mc007-1.jpg If the system is at dynamic equilibrium, which statement is true? Sublimation of the NH4CI crystals stops. Solidification of the NH4CI vapors stops. The rate of sublimation of the NH4CI crystals is equal to the rate of solidification of the NH4CI vapors. The rate of sublimation of the NH4CI crystals is higher than the rate of solidification of the NH4CI vapors.

The rate of sublimation of the NH4CI crystals is equal to the rate of solidification of the NH4CI vapors.

The reaction below is at dynamic equilibrium. mc004-1.jpg Which statement is true for the equilibrium system? The concentration of NH3 is greater than the concentration of N2. The concentration of NH3 equals the concentration of N2. The rate of the forward reaction equals the rate of the reverse reaction. The rate of the forward reaction is greater than the rate of the reverse reaction.

The rate of the forward reaction equals the rate of the reverse reaction.

In the atmosphere, under the effect of ultraviolet rays, oxygen molecules combine to form ozone molecules, and ozone molecules also photodissociate to form oxygen molecules. Which of the following would be observed if this reaction is in dynamic equilibrium? The concentration of oxygen will increase. The concentration of ozone will decrease. The rates of the forward and reverse reactions will increase. The rates of the forward and reverse reactions will remain the same.

The rates of the forward and reverse reactions will remain the same.

Consider the general reversible reaction. mc011-1.jpg What is the equilibrium constant expression for the given system? mc011-2.jpg mc011-3.jpg mc011-4.jpg mc011-5.jpg

[C]c [D]d over [A]a [B]b