The correct option is A 1.82
For monobasic acid, by applying Ostwald's dilution law equation, [H+]=√c×Ka.
Substituting the given values in the above equation,
[H+]=√(0.01×2.24×10−2)=0.014966M.
The pH is a negative logarithm of hydrogen ion concentration.
pH=−log[H+]=−log(0.014966)=1.82.