Why awe elementary reactions involving three or more reactants very uncommon?

Ozone, O3, in the Earths upper atmosphere decomposes according to the equation 2 O3(g) 3 O2(g) The mechanism of the reaction is thought to proceed through an initial fast, reversible step followed by a slow, second step. Step 1: Fast, reversible O3(g) O2(g) + O(g) Step 2: Slow O3(g) + O(g) 2 O2(g) (a) Which of the steps is rate-determining? (b) Write the rate equation for the rate-determining step

The following statements relate to the reaction for the formation of HI: H2(g) + I2(g) 2 HI(g)Rate = k[H2][I2] Determine which of the following statements are true. If a statement is false, indicate why it is incorrect. (a) The reaction must occur in a single step. (b) This is a second-order reaction overall. (c) Raising the temperature will cause the value of k to decrease. (d) Raising the temperature lowers the activation energy for this reaction. (e) If the concentrations of both reactants are doubled, the rate will double. (f) Adding a catalyst in the reaction will cause the initial rate to increase.

The label on a bottle of 3% (by volume) hydrogen peroxide, H2O2, purchased at a grocery store, states that the solution should be stored in a cool, dark place. H2O2decomposes slowly over time, and the rate of decomposition increases with an increase in temperature and in the presence of light. However, the rate of decomposition increases dramatically if a small amount of powdered MnO- is added to the solution. The decomposition products are H2O and O2. MnO2 is not consumed in the reaction. Write the equation for the decomposition of H2O2. What role does MnO2 play? In the chemistry lab, a student substituted a chunk of MnO2 for the powdered compound. The reaction rate was not appreciably increased. WTiat is one possible explanation for this observation? Is MnO2 part of the stoichiometry of the decomposition of H2O2?