試題詳解

8. The thermal decomposition of PH3 into phosphorus and molecular hydrogen (4 PH₃ → P₄+6 H₂) is a first-order reaction. If the half-life of the reaction is 35.0 seconds at 680°C, calculate the time required for 90% of the original PH₃ to decompose.
(A) 5.00 seconds
(D) 116 seconds
(B) 96.0 seconds
(E) 173 seconds
(C) 108 seconds