Question

calculate the molarity of a solution containing 10g of NaOH in 50cm3 of solution

Answer 1

Given:-

→ Mass of NaOH [solute] = 10g

→ Volume of solution = 50cm³

To find:-

→ Molarity of the solution.

Solution:-

• Molar mass of Sodium (Na) = 23g/mol

• Molar mass of Oxygen (O) = 16g/mol

• Molar mass of Hydrogen (H) = 1g/mol

Hence, molar mass of NaOH :-

= 23 + 16 + 1

= 40g/mol

Number of mole in 10g of NaOH :-

= Given Mass/Molar mass

= 10/40

= 0.25 mole

Now, let's convert the volume of the solution from cm³ to L.

=> 1cm³ = 0.001L

=> 50cm³ = 50(0.001)

=> 0.05 L

Molarity of a solution :-

= Moles of solute/Liters of solution

= 0.25/0.05

= 25/5

= 5 M

Thus, molarity of the solution is 5M .