A certain substance A is mixed with equimolar quantity of substance B. At the end of an hour, A is 75% reacted. Calculate the time when A is 10% underacted. Given: order of reaction is zero.)

A certain substance A is mixed with equimolar quantity of substance

1.	A certain substance A is mixed with equimolar quantity of substance B. At the end of an hour, A is 75% reacted. Calculate the time when A is 10% underacted. Given: order of reaction is zero.)
Answer» EXPLANATION:According to zero ORDER REACTION: x=kt ( x = AMOUNT of reactant reacted) 75=k×1 and 90=k×t So t=90/75=1.2 hr