Calculate the [OCl-] of a 7.03×10-2 M solution of the weak acid HClO (make an approximate calculation assuming that initial concentration is equal to the equilibrium concentration). Round your answer to 3 significant digits.

HClO = OCl- + H+

.....HOCl ==> H^+ + OCl^-

I...7.2E-2....0.....0
C....-x.......x.....x
E..7.2E-2 -x..x......x

Ka = (H^+)(OCl^-)/(HClO)
Substitute and solve for x