JEE Advanced levelOne or more correct optionsDifficulty 3 of 3ie109
Which statement(s) about dilution of strong base NaOH at 298 K is/are correct? (Solve exactly with water ionisation when needed; give pH to two decimals.)
A10−3MNaOH diluted 1000-fold has pH 8.00.
B10−8MNaOH has pH 7.02.
C0.1MNaOH diluted 100-fold has pH 11.
D10−8MNaOH has pH 6.
Answer: A, B, C
0.1→10−3M gives pOH 3, pH 11. 10−6M: [OHX−]=1.0099×10−6, pH =8.00. 10−8M: solving y(y+10−8)=10−14 for [HX+]=y gives [OHX−]=1.051×10−7M, pOH=6.98 and pH=7.02. A base can never give pH below 7.