Answer to Question #342626 in General Chemistry for Nicole

Question

Direction: Answer the following questions:

1. What unit is used to describe reaction rate?\

2. In a reaction between Mg and hydrochloric acid

Mg (s) + HCl (aq) --> MgCl₂ (aq) + H₂ (g)

The data below was recorded. Examine the data. What is the average rate of reaction?

Time Mass of Magnesium

0 0.012

2 0.010

6 0.006

8 0.004

Answer 1

The units of the rate constant, k, depend on the overall reaction order. The units of k for a zero-order reaction are M/s, the units of k for a first-order reaction are 1/s, and the units of k for a second-order reaction are 1/(M·s).

Second-order kinetics describes the rate of a chemical reaction that is proportional to the product of the concentrations (in moles) of two of the reactants (also known as bimolecular kinetics), or to the square of the molar concentration of the reactant if there is only one.