Answer to Question #205247 in Chemistry for Sam

Question

How many grams of Na₂SO₄ is needed to prepare a 2.0 L of 0.1 M Na₂SO₄?

Question 2 options:

A) 

28.2

B) 

7.05

C) 

56.4

D) 

14.1 

Answer 1

C_M = n / V

n (Na₂SO₄) = C_M x V = 0.1 x 2.0 = 0.2 mol

n = m / M

M (Na₂SO₄) = 142.04 g/mol

m (Na₂SO₄) = n x M = 0.2 x 142.04 = 28.2 g

Answer: A) 28.2