Answer: The final molarity of a 20mL- 1.3M salt solution after it has been diluted with 100ml water is 0.22 M
Explanation:
According to the dilution law,
[tex]M_1V_1=M_2V_2[/tex]
where,
[tex]M_1[/tex] = molarity of stock solution = 1.3 M
[tex]V_1[/tex] = volume of stock solution = 20 ml
[tex]M_1[/tex] = molarity of diluted solution = ?
[tex]V_1[/tex] = volume of diluted solution = (20+100) ml = 120 ml
Putting in the values we get:
[tex]1.3\times 20=M_2\times 120[/tex]
[tex]M_2=0.22M[/tex]
Therefore the final molarity of a 20mL- 1.3M salt solution after it has been diluted with 100ml water is 0.22 M