Answer: a) 0.15 M
Explanation:
According to the dilution law,
\(M_1V_1=M_2V_2\)
where,
\(M_1\) = molarity of stock solution = 0.50 M
\(V_1\) = volume of stock solution = 250 ml
\(M_2\) = molarity of diluted solution = ?
\(V_2\) = volume of diluted solution = 840 ml
Putting in the values, we get:
\(0.50M\times 250=M_2\times 840\)
\(M_2=0.15\)
Therefore, the molarity of the resulting solution is 0.15 M
