What is the molarity of a 2.1g sample of Lithium Carbonate that is dissolved in 500mL of water?

Answer 1

Molarity is defined as moles of solute per Liter of solution. Convert g of Li₂CO₃ to moles using its MW. Then divide moles by the volume in L to obtain the molarity.

MW of Li₂CO₃ = 73.89 g/mol

2.1 g Li₂CO₃ x (1 mol Li₂CO₃ / 73.89 g Li₂CO₃) = 0.028 mol Li₂CO₃

V in L = 500 mL x (1 L / 1000 mL) = 0.5 L

M = mol/L = 0.028 / 0.5 = 0.056 M ~ 0.06 M Li₂CO₃ (rounded to 1 significant figure)