Question

The molarity of urea (molar mass 60 g mol⁻¹) solution by dissolving 15 g of urea in 500 cm³ of water is ______.

Options

• 2 mol dm⁻³

• 0.5 mol dm⁻³

• 0.125 mol dm⁻³

• 0.0005 mol dm⁻³

Answer 1

The molarity of urea (molar mass 60 g mol⁻¹) solution by dissolving 15 g of urea in 500 cm³ of water is 0.5 mol dm⁻³.

Explanation:

Urea (molar mass) = 60 g/mol

Molarity = `("No. of moles of solute")/("Volume of solution in (L)")`

= `(15 xx 1000)/(60 xx 500)`

= `15/(6 xx 5)`

= `15/30`

= `1/2`

= 0.5 mol dm⁻³