The reaction between Cr2O72- and HNO3 in an acidic medium is  Cr2O72- + 5H+ + 3HNO2 → 2Cr3+ + 3NO3- + 4H2O The rate of disappearance is found to be 2.4 x 10-4 mol L-1 s-1, during the measured time interval. Find the rate of reaction.

7.2 x 10-4 mol L-1 s-1 4.8 x 10-4 mol L-1 s-1 3.6 x 10-4 mol L-1 s-1 2.4 x 10-4 mol L-1 s-1

2.4 x 10-4 mol L-1 s-1

Rate = -\(\frac{d[Cr_2O_7^{2-}]}{dt}\) = -(-2.4 x 10-4) = 2.4 x 10-4 mol L-1 s-1