See image — AITS & Test Series Chemistry Question

💡 Solution & Explanation

   o o A g 4B g 3C g At t 0 : P 0 0 At t 20min : P x 4x 3x      o o P x 4x 3x 400 P 6x 400 6x 400 100 300            x = 50 4 1 12