Question :
21) 0.56 mol of NO and 0.38 mol of Br2 : 1282446
21) 0.56 mol of NO and 0.38 mol of Br2 are placed in a container and allowed to react until equilibrium is established. At equilibrium there is 0.47 mol of NOBr present
2 NO (g) + Br2 (g) 2 NOBr (g)
What is the composition of the equilibrium mixture in terms of moles of each substance present?
A) 0.09 mol NO0.15 mol Br2
B) 0.33 mol NO0.09 mol Br2
C) 0.56 mol NO0.38 mol Br2
D) 0.47 mol NO0.47 mol Br2
22) In writing an equilibrium constant expression which of the following is incorrect?
A) Product concentrations are always placed in the numerator of the expression.
B) Concentrations are always expressed as molarities.
C) Concentrations of pure solids and pure liquids, when placed in the equilibrium expression, are never raised to any power.
D) Reactant concentrations are always placed in the denominator of the expression.
23) Given the following reaction, the equilibrium expression will be:
4 CuO (s) + CH4 (g) CO2 (g) + 4 Cu (s) + 2 H2O (g)
A) [CH4]/[CO2][H2O]2
B) [CuO]4/[Cu]4
C) [Cu]4/[CuO]4
D) [CO2][H2O]2 /CH4]
24) Which of the following is the correct equilibrium expression for the reaction
CS2 (g) + 4 H2 (g) CH4 (g) + 2 H2S (g)
A)
B)
C)
D)
25) Which of the following is the correct equilibrium expression for the reaction
2 Ag (s) + Cl2 (g) 2 AgCl (s)
A)
B)
C)
D)
26) Identify the reaction that is described by the following equilibrium expression:
K = [H2]2 [O2]/[H2O]2
A) 2 H2 (g) + O2 (g) 2H2O (g)
B) H2O (g) H2 (g) + ½ O2 (g)
C) H2O (g) 2H (g) + O (g)
D) 2H2O (g) 2 H2(g) + O2 (g)
27) If, at equilibrium, most of the reactants remain unreacted, the equilibrium constant would be expected to have ________.
A) a very large numerical value
B) a very small numerical value
C) a numerical value slightly greater than 1.0
D) a numerical value slightly less than 1.0
28) When the position of an equilibrium is described as being “far to the left” it means that ________.
A) very few reactant molecules are present in the equilibrium mixture
B) very few product molecules are present in the equilibrium mixture
C) significant amounts of both products and reactants are present in the equilibrium mixture
D) the rate of the reverse reaction is greater than that of the forward reaction
29) The grams of products present after a chemical reaction reaches equilibrium ________.
A) will always be greater than the grams of reactants present
B) will always be less than the grams of reactants present
C) must equal the grams of reactants present
D) may be less than, equal to, or greater than the grams of reactants present, depending upon the chemical reaction under study
30) Which statement is false? An equilibrium constant for a particular reaction:
A) changes when the temperature increases.
B) changes when a catalyst is added.
C) does not change when an additional quantity of a reactant is added.
D) does not change when a product is removed.
