chemistry question

Question

you weigh 25.8 grams of BeCl2 and dissolves it in water to a final volume of 200mL. assuming ally he salt dissolves, what is the molarity of this BeCl2 solution?

Answer 1

First we need the molecular weight of BeCl2:

Be - 9.01 g/mol

Cl - 35.45 g/mol;

BeCl₂ = 9.01 + 2(35.45) = 79.91 g/mol

Now Molarity = moles/ liter and 1 Liter = 1000 ml to find the answer through dimensional analysis canceling out units as we go..

25.8 g BeCl₂ x 1 mole x 1000 mL = 1.61 moles/L = 1.61 M

200 mL 79.91 g 1 L