Integrated Rate Law Calculations: 1st Order

Question

The decomposition of dinitrogen pentoxide in carbon tetrachloride solution at 30 °C

N₂O₅2 NO₂ + ½ O₂

is first order in N₂O₅ with a rate constant of  .00410min^-1.

If the initial concentration of N₂O₅ is 1.13 M, the concentration of N₂O₅ will be .228 M after _______min have passed.

Answer 1

We can use the following equation to find the time: ln [N2O5]₀/[N2O5]_t = kt.

ln(1.13/0.228) = 0.00410 t

Solve for t

t = 1.60/0.0041 min^-1 = 390 min.