GATE Exam Questions - Engineering

Q1:

A wastewater sample contains 10-5.6 mmol/l of OH ions at 25° C. The pH of this sample is

A 8.6

B 8.4

C 5.6

D 5.4

ANS:D - 5.4

poh = 8.6.

As the mmol will change to mole per lit;
therefore as we know;
pH + pOH = 14.
pH + 8.6 = 14.
pH = 14 - 8.6 = 5.4.