NEET Solved Paper 2018 Question 29
Question: Following solutions were prepared by mixing different volumes of NaOH and HCl of different concentrations : [NEET - 2018]
A. $ 60mL\frac{M}{10}\text{HCl+40mL}\frac{M}{10}NaOH $ B. $ 55mL\frac{M}{10}\text{HCl+45mL}\frac{M}{10}NaOH $ C. $ 75mL\frac{M}{5}\text{HCl+25mL}\frac{M}{5}NaOH $ D. $ 100mL\frac{M}{10}\text{HCl+100mL}\frac{M}{10}NaOH $ pH of which one of them will be equal to 1?
Options:
A) D
B) A
C) B
D) C
Show Answer
Answer:
Correct Answer: D
Solution:
- Meq of $ \text{HCl=75}\times \frac{1}{5}\times 1=15 $
Meq of $ \text{NaOH=25 }\times\frac{1}{5}\times\text{ 1=5} $
Meq of HCl in resulting solution =10
Molarity of $ [{H^{+}}] $ in resulting mixture $ \text{=}\frac{10}{100}=\frac{1}{10} $ $ \text{pH=-log }[{H^{+}}]=-\log [ \frac{1}{10} ]=1.0 $
