Verified Solution • 2025–26 Session
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QNEET-2018-Ch-866: NEET 2018 Chemistry - Class 11 NEET-2018-Ch-866 Solution: Following solutions were prepared by mixing different volumes…
Following solutions were prepared by mixing different volumes of NaOH and HCl of different concentrations: A. 60 mL HCl + 40 mL NaOH B. 55 mL HCl + 45 mL NaOH C. 75 mL HCl + 25 mL NaOH D. 100 mL HCl + 100 mL NaOH pH of which one of them will be equal to 1? B A D C
Multiple Choice Options
- A B
- B A
- C D
- D C
Step-by-Step Verified Solution
(A) 60 mL M 10 HCl + 40 mL M 10 NaOH
Mili. moles of HCl = 60 _ 1 10 = 6
Mili. moles of NaOH = 40 _ 1 10 = 4
Mili. moles of HCl remaining = 6 - 4 = 2
Total volume will be 60 + 40 = 100 mL
Concentration of [H + ] = 2 100 = 2 _ 10 -2
_ pH = 2 - log2 = 1.7
(B) 55 mL M 10 HCl + 45 mL M 10 NaOH
Mili. moles of HCl = 55 _ 1 10 = 5.5
Mili. moles of NaOH = 45 _ 1 10 = 4.5
Mili. moles of HCl remaining = 5.5 - 4.5 = 1
Concentration of [H + ] = 1 100 = 10 -2
_ pH = 2
(C) 75 mL M 5 HCl + 25 mL M 5 NaOH
Mili. moles of HCl = 75 _ 1 5 = 15
Mili. moles of NaOH = 25 _ 1 5 = 5
Mili. moles of HCl remaining = 15 - 5 = 10
Total volume will be 75 + 25 = 100 mL
Concentration of [H + ] = 10 100 = 10 -1
_ pH = 1
(D) 100 mL M 10 HCl + 100 mL M 10 NaOH
Mili. moles of HCl = 100 _ 1 10 = 10
Mili. moles of NaOH = 100 _ 1 10 = 10
Mili. moles of HCl remaining = 10 - 10 = 0
So, it is neutral solution.
_ pH = 7