Question

A solution is prepared by adding 2g of a substance A to 18g of water.calculate the mass presebt of the solute

Answer 1

Answer:

Mass percent of

A=Mass of A/Mass of solution ×100

=2g/2g of A+18g of water×100

=2g/20g×100

=10%

Answer 2

Answer :

Given -

• Amount of Solute = 2 g
• Amount of Solvent = 18 g

To Find -

• Mass per cent ?

Solution -

Mass percent = (Mass of Solute/Mass of Solution) × 100

➸ (2 g/2 g + 18 g) × 100

➸ (2 g/20 g) × 100

➸ (1/10) × 100

➸ 10 %

So, the mass per cent of Solute = 10 %.

SOME FORMULAS -

• Mole fraction of A = No. of moles of A/No. of moles of Solution.
• Mole fraction of B = No. of moles of B/No. of moles of Solution.
• Molarity = No. of moles of Solute/Volume of Solution in litres.
• Molality = No. of moles of Solute/Mass of solvent in kg.