在间歇反应器中进行等温二级反应A&rarr;B，<img src="https://nimg.ppkao.com/2019-05/tangling/2019051717202776462.jpg?sign=e7e3de0526e5c45055bf1663a41ac92e&t=62d6084b" />，当<img src="https://nimg.ppkao.com/2019-05/tangling/2019051717211127168.jpg?sign=210932e07a5f750748e589f38d6d3c45&t=62d6084b" />时，求反应至<img src="https://nimg.ppkao.com/2019-05/tangling/2019051717212947763.jpg?sign=26afac680d3d94db8f092b41f273a64d&t=62d6084b" />所需时间t=（）秒。