Question

What is the concentration of a solution prepared by placing 20. mL of 0.12 M K2S in a graduated cylinder and pouring water until you reach the 100.0 mL mark (the final volume after mixing the solution with water is 100.0 mL).

Answer 1

Answer: 0.024 M

Explanation:

According to the neutralization law,

$M_1V_1=M_2V_2$

where,

$M_1$ = molarity of stock solution = 0.12 M

$V_1$ = volume of stock solution = 20.0 ml

$M_2$ = molarity of diluted solution = ? M

$V_2$ = volume of diluted solution = 100.0 ml

Putting in the values we get:

$0.12M\times 20.0=M_2\times 100.0$

$M_2=0.024$

Therefore, the concentration of the resulting solution is 0.024 M.