Solving a word equation?

Question

do you know how many milliliters of 0.256 M KCl solution will contain the following?

a) 0.761 mol of KCl
b) 31.8 g of KCl

Answer 1

0.256 M KCl contains 0.256 moles of KCl in 1 L
0.761 mole / 0.256 moles per liter = 2.973 L or 2973 mL

MW KCl = 74.557
31.8 g KCl / 74.557 = 0.4265 moles
0.4265 moles / 0.256 moles per liter = 1.666 L or 1666 mL

Answer 2

Set up ratios and solve

0.256 M KCl contains 0.256 moles dissolved in 1,000 mL of solution.

Calcualte the molar mass of KCl. Multiply by 0.256 and you have grams per 1,000 mL.

With this information, you can set the ratios and solve your 2 questions