Chemistry exam 2

The reaction is first order in H2 and second order in No at a particular temp. What is the rate law? 2H2(g)+2NO(g)--->2H2O(g)+N2(g)

Rate=k[H2][NO]^2

A solution has pOH of 5.34. What is its hydroxide ion concentration?

4.6x10^-6

For the hypothetical reaction 2A+B--->2C+D, the initial rate of disappearance of A is 2.0x10^-2 mol/Ls. What is the initial rate of disappearance of B? A. 1x10^-2 B. 1.4x10^-1 C. 4.0x10^-4 D. 1.4x10^-2 E. 8.0x10^-2

A. 1x10^-2

Two substances A and B react with each other in such a way that 1/2 of A remains after 25 min and 1/4 of A remains after 50 min. Doubling the concentration of B while keeping the concentration of A fixed doubles the rate of the reaction. This reaction is... A. first order in A and B B. zero order in A and B C. first order in A and second order in B D. second order in A and B E. second order in A and first order in B

A. first order in A and B

Which of the following statements is always true? A. the rate constant is independent of the concentrations of the reacting species B. the rate law can be determined from the stoichiometric equation C. the rate for a reaction depends on the concentrations of all the reactants D. the rate of a catalyzed reaction is independent of the concentration of the catalyst E. exothermic reactions have lower activation energies than endothermic reactions

A. the rate constant is independent of the concentrations of the reacting species

What is the Kp equilibrium constant expression for the following equilibrium? Ti(s)+2Cl2(g)<------>TiCl4(s) A. (PCL2)^2 B. 1/(PCl2)^2 C. PCl2 D. 1/PCl2 E. PTiCl4/PTi(PCl2)^2

B. 1/(PCl2)^2

The complete mechanism, for a reaction is considered to occur in two steps, one is slow and the other fast A+2B--> C+D A+C-->E+F What is the net chemical equation predicted by this mechanism

B. 2A+2B--->D+E+F

The pOH of a system is 5.58. What is the pH of the solution? A. 2.51 B. 8.42 C. 2.63 D. 5.58 E. 7.00

B. 8.42

Which of the following statements is incorrect concerning a catalyst? A. there is no net consumption of a catalyst in a reaction B. A catalyst alters the equilibrium distribution of reactants and products C. A catalyst may appear in the rate law for a reaction D. A catalyst decreases the activation energy of a reaction E. a catalyst provides an alternative reaction mechanism

B. a catalyst alters the equilibrium, distribution of reactants and products

Which of the following statements is true concerning the reaction given below? 2H2S(g)+O2(g)---->2S(s)+2H2O(g) A. the rate law is Rate=k[H2S]^2[O2] B. the rate law may be determined only by experiment C. The rate law is Rate=k[H2S][O2] D. the reaction is first order in H2S and second order in O2 E. the reaction is second order in H2S and first order in O2

B. the rate law may be determined only by experiment

The reaction quotient for a system is 2.8x10^-4. If the equilibrium constat for the system is 6.2x10^3, what will happen as the reaction approaches equilibrium? A. equilibrium constant will increase until it equals the reaction quotient B. there will be a net loss in reactants C. there will be a net loss in both products and reactants D. there will be a net loss in products E. the equilibrium constant will decrease until it equals the reaction quotient

B. there will be a net loss in reactants

Which of the following species is amphiprotic in aqueous solution? A. NH4^+ B. CH3NH2 C. HSO3^- D. H3O^+ E. F^-

C. HSO3^-

Solid HgO, liquid Hg and gaseous O2 are placed in a glass bulb and allowed to reach equilibrium. The amount of Hg(l) in the bulb could be increased by.... A. adding an inert gas B. adding some HgO(s) C. increasing the temp D. removing some HgO(s) E. by increasing the pressure

C. increasing the temp

Which of the following statements is true in a reaction system at equilibrium? A. the number of collisions per unit time between reactants is equal to the number of collisions per unit time between products B. the equilibrium constant is 0 C. reactants are reacting to form products at the same rate as products are reacting to form reactants D. the product of the concentrations of the products divided by the product of the concentrations of the reactants is always a constant E. reactants and products are present in equimolar amounts

C. reactants are reacting to form products at the same rate as products are reacting to form reactants

The half life of a reaction is... A. the time it takes for the amount of product formed to equal half the initial amount of reactant. B. twice as long for a second order reaction as it is for a first order reaction C. the time it takes for the reactant concentration to decrease to 1/2 its initial value D. one half of the time the reaction will take to go to completion E. how long the reaction can run before stopping

C. the time it takes for the reactant concentration to decrease to 1/2 its initial value

The balanced chemical equation and rate law for the reaction at a particular temp are Rate=k[NO]^2[H2] 2NO(g)+2H2(g)--->N2(g)+2H2O(g) what is the reaction order wit respet to nitric oxide? A. 4 B. 0 C. 1 D. 2 E. 3

D. 2

What is the conjugate acid of H2PO4^-(aq)? A. PO4^3- B. HPO4^2- C. H3O^+ D. H3PO4 E. H3P

D. H3PO4

A __________ is a substance that increases the rate of a reaction but is not consumed by it. A. dark matter B. pansmer C. beta particle D. catalyst E. antimatter

D. catalyst

Which of the following is/are true concerning a chemical reaction AT EQUILIBRIUM? 1. the system will be a mixture of reactant and products 2. the rate of the forward and reverse reactions are equal 3. the amount of each reactant and product are contstant A. 1 only B. 2 only C. 3 only D. 1 and 2 E. 1,2, and 3

E. 1, 2, and 3

Which acid has the strongest conjugate base in aqueous solution? A. HI B. H2SO4 C. HClO4 D. HNO3 E. HF

E. HF (bc weakest acid)