Q.
A drop of solution (volume 0.05 mL) contains 3.0×10−6 moles of H+. If the rate constant of disappearance of H+ is 1.0×107molelitre−1sec−1. How long would it take for H+ in drop to disappear:
time Total for drop to disappears(a0−at)=ktat=0 (0.05×10−3)×1.0×1073.0×10−6=t100% ⇒t100%=6×10−9 sec
Alternative method Units rate constant =molL−1sec−1⇒ Zero order reaction [A0]−[A]=kT[A0]=0.05×10−33×10−6×100=503 503−0=kT ⇒t=503×110−7 =6×10−9 sec