Question

What is the molarity of a solution prepared by dissolving 1.56 g of gaseous hcl (molar mass = 36.5 g into enough water to make 26.8 ml of solution?

Answer 1

Molar mass HCl : 36.5 g/mol

number of moles:

n  = mass solute / molar mass

n = 1.56 / 36.5

n =0.0427 moles

Volume in liters : 26.8 mL / 1000 => 0.0268 L

therefore:

Molarity  = moles solute / volume 

Molarity =  0.0427  / 0.0268 => 1.593 M