The initial concentration of a reactant in a first order reaction is 0.620 M.  What will be its concentration after 3 half-lives have passed?

An isomerization reaction of a substance, A, is first order.  In a laboratory class one student group found that 28.5% of A had isomerized after a period of 15.0 minutes when the temperature was maintained at 84.5 °C.  What is the half-life of substance A at that temperature? 

The reaction, 2 SO3(g)  2 SO2(g)  +  O2(g) is endothermic.  Predict what will happen if the temperature is increased.

Most heterogeneous reactions are slower than similar homogeneous reactions.  Which of the following best explains why?

The equilibrium constant, Kp, has a value of 6.5 × 10–4 at 308 K for the reaction of nitrogen monoxide with chlorine. 2NO(g) + Cl2(g)  2NOCl(g) What is the value of Kc?  

The reaction system CS2(g) + 4H2(g)  CH4(g) + 2H2S(g) is at equilibrium. Which of the following statements describes the behavior of the system if the partial pressure of carbon disulfide is reduced?  

The equilibrium law for the system, CaO(s)  + CO2(g) CaCO3(s), is

A reaction has the rate law, rate = k3.  What is the overall order of the reaction?

A reaction has the rate law, rate = k2.  Which change will cause the great­est in­crease in the reaction rate?

In a chemical reaction system that has reached equilibrium, the concentrations of the various spe­cies are constantly changing even though the total number of molecules is unchanging.  ___