Question

0.76 g of glucose (molecular mass = 180 g mol⁻¹) is dissolved in 20 ml of aqueous solution at 298 K (R = 0.0821 L atm K⁻¹ mol⁻¹).

What is the molarity of glucose solution?

Options

• 0.42 M

• 0.21 M

• 4.01 M

• 2.02 M

Answer 1

0.21 M

Explanation:

Given: Mass of glucose = 0.76 g

Molar mass of glucose = 180 g/mol

Volume of solution = 20 mL = 0.020 L

Moles of glucose = `0.76/180` = 0.00422 mol

Molarity (M) = `0.00422/0.020`

= 0.211 mol/L