Which of the following solutions will have pH close to 1.0 ?

Options

A. 100 ml of M/10 HCl + 100 ml of M/10 NaOH
B. 55 ml of M/10 HCl + 45 ml of M/10 NaOH
C. 10 ml of M/10 HCl + 90 ml of M/10 NaOH
D. 75 ml of M/5 HCl + 25 ml of M/5 NaOH

Answer

4

Explanation

The answer has to be either (b) or (d) since only in these two choices, HCl is greater than NaOH (only when HCl is in greater amount , pH can be acidic ).
In (b) , 10 ml of M/10 HCl will be left out after neutralization . `[H^(+)] = (10 xx M/10)/100 = 0.01 M` .
` :. pH = 2`