Question

Samantha added 125 mL of water to 100mL of a stock solution to make 225 mL of a 0.75 M Solution.The Concentration of the original stock solution will be __ than that of the mixed solution.

A.Greater than

B.Less than

C.Equal to

Answer 1

Answer: A.Greater than

Explanation:

According to the neutralization law,

$M_1V_1=M_2V_2$

where,

$M_1$ = molarity of stock  solution = ?

$V_1$ = volume of stock  solution = 100 ml

$M_2$ = molarity of dilute solution = 0.75 M

$V_2$ = volume of dilute solution = 225 ml

$M_1\times 100=0.75\times 225$

$M_1=1.7M$

Thus Concentration of the original stock solution will be greater than that of the mixed solution.