Dinitrogen pentoxide, N 2 O 5 , decomposes when heated in carbon tetrachloride solvent. If the rate constant for the decomposition of N 2 O 5 is 6.2 × 10-4 min -1 , what is the half-life? (The rate law is first order in N 2 O 5 .) How long would it take for the concentration of N 2 O 5 to decrease to 25% of its initial value? to 12.5% of its initial value?