Answer:
Molality of the diluted sample is 0.778 M
Explanation:
Given -
Molality of the original solution = 3.5 M
Volume of the original solution = 20 mL
Volume of the diluted solution = 90 mL
Molality of the diluted sample = X
As we know
Molality of the original solution * Volume of the original solution = Volume of the diluted solution * Molality of the diluted sample
Substituting the given values, we get -
[tex]3.5 * 20 = 90 * X\\X = 0.778[/tex]M
Molality of the diluted sample is 0.778 M