$$t = {{4.606} \over k}$$

$$t = {{2.303} \over k}$$

$$t = {{0.693} \over k}$$

$$t = {{6.909} \over k}$$

$$ - {{d\left[ {{N_2}} \right]} \over {dt}} = 2{{d\left[ {N{H_3}} \right]} \over {dt}}$$

$$ - {{d\left[ {{N_2}} \right]} \over {dt}} = {1 \over 2}{{d\left[ {N{H_3}} \right]} \over {dt}}$$

$$3{{d\left[ {{H_2}} \right]} \over {dt}} = 2{{d\left[ {N{H_3}} \right]} \over {dt}}$$

$$ - {1 \over 3}{{d\left[ {{H_2}} \right]} \over {dt}} = -{1 \over 2}{{d\left[ {N{H_3}} \right]} \over {dt}}$$

the rate of a first-order reaction does not depend on reactant concentrations; the rate of a second-order reaction does depend on reactant concentrations

the half-life of a first-order reaction does not depend on [A]₀ ; the half-life of a second order reaction does depend on [A]₀

a first-order reaction can be catalysed; a second-order reaction cannot be catalysed

the rate of a first-order reaction does depend on reactant concentrations; the rate of a second-order reaction does not depend on reactant concentrations

is halved

is doubled

is tripled

remains unchanged.