dx 反应净速率y= =r+-r. dt =k+(a-x)2-kx2 dx k.(a-x)-kxi-fdi (c)平衡条件:r+=r k:(a-xe)2=kxe2 x K- k (a-x2)2 k 2222 反应净速率 dt dx = =r+-r- =k+(a-x)2 -kx 2 = + − − − x t dt k a x k x dx 0 0 2 2 ( ) (c)平衡条件:r+=rk+(a-xe)2 = kxe 2 − + = − = k k a x x K e e 2 2 ( )