In a second$-$order elementary reaction $A+BC,$ the initial concentrations of A and $B$ are both $1\mathrm{.}0mo\frac{l}{L}.$ After $30$ minutes, the concentration of A decreases to $0\mathrm{.}6mo\frac{l}{L}.$ Determine the rate constant and the time required to reach $75\%$ completion.

For the reversible reaction $A+BC+D,$ the initial concentrations of A and $B$ are $0\mathrm{.}2M$ each, and $C$ and $D$ are both $0M.$ At equilibrium, the concentration of $C$ is $0\mathrm{.}15M.$ Calculate the equilibrium constant.

The rate constant of a reaction is $0\mathrm{.}1s^{-1}$ at $300K$ and $0\mathrm{.}2s^{-1}$ at $310K.$ Use the Arrhenius equation to