A chemist wants to make 6.5 L of a. 350M CaCl2 solution. What mass of CaCl2 (in g) should the chemist use?

First M stands for Molarity which is (moles of solute) / (Liters of solution). we also know that moles = (mass) / (molar mass). so we can form some equations here. We know:

Molarity (M) = moles (mol) / Liters (L)

moles (mol) = (mass) / (molar mass)

we can substitute the (mass) / (molar mass) for (moles) and get:

M = [ (mass) / (molar mass) ] / Liters

we can now isolate mass and get

M * Liters * molar mass = mass

now we need to find the molar mass of CaCl2 which is 110.98 g/mol

plug the values in and get

.350M * 6.5L * 110.98 g/mol = mass

mass = 252.4795g however the 6.5L has only 2 sig figs so i would say

mass CaCl2 = 2.5 * 10 ^2 g