Question

The molarity of a solution obtained by mixing $250ml$ of $0.5MHCl$ with $750ml$ of $2MHCl$ is:

• A. 1.8
• B. 2
• C. 1.6
• D. 0.8

Answer 1

Answer: (C)

1.6

No. of moles in $0.5M$ solution of $250mlHCl=0.5\times 250=125moles$
No. of moles in $2M$ solution of $750mlHCl=2\times 750=1500moles$

Total number of moles $=1500+125=1625moles$

Total volume $=250+750=1000ml$

$\therefore$ Molarity of the resulting solution $=\frac{1625}{1000}=1.6M$