If 250 mL of a 0.50 M NaCl solution is diluted to 840 mL, what is the molarity of the resulting solution?
a) 0.15 M
b) 6.7 M
c) 0.60 M
d) 1.7 M
e) 0.0025 M



Answer :


Convert all the mL to L first, .25 L and .84 L  (.25) (.5) = (.84) (x) solve... I got .148809524, round to one sig fig (i think) would be .1 M

Answer: a) 0.15 M

Explanation:

According to the dilution law,

[tex]M_1V_1=M_2V_2[/tex]

where,

[tex]M_1[/tex] = molarity of stock solution = 0.50 M

[tex]V_1[/tex] = volume of stock solution = 250 ml

[tex]M_2[/tex] = molarity of diluted solution = ?

[tex]V_2[/tex] = volume of diluted solution = 840 ml

Putting in the values, we get:

[tex]0.50M\times 250=M_2\times 840[/tex]

[tex]M_2=0.15[/tex]

Therefore, the molarity of the resulting solution is 0.15 M