Answer to Question #27284 in Chemistry for

Question

How many grams of beryllium chloride are needed to make 125mL of a 0.050 M solution

Answer 1

The equation needed to calculate theconcentration is

C(M) = n(mol) / V(L)

C - concentration (M)
n - amount of BeCl₂ (mol)
V - volume (L)

n(mol) = C(M) x V(L) = 0.050 x 0.125 = 6.25 x 10^-3 mol

The mass of BeCl₂ is

m(g) = n(mol) x M_W(g/mol)

M_W(BeCl₂) = 9.01 + 2 x 35.5 = 80.01 g/mol
m(BeCl₂) = 6.25 x 10^-3 x 80.01 = 0.500 g

Answer: m(BeCl₂) = 0.500g