Question

calculate the molality of solution when 80g NaOH is dissolved in 600 mL of water​

Answer 1

Answer:-

3.33 m

Explanation:-

Given:-

→Mass of NaOH (solute) = 80g

→Volume of water (solvent) = 600ml

To find:-

→Molality of the solution.

Solution:-

Molar mass of NaOH:-

= 23 + 16 + 1

= 40g

Number of moles in 80g of NaOH:-

= Given mass/Molar mass

= 80/40

= 2 moles

Thus, 2 moles are there in 80g of NaOH.

Now, let's calculate the mass of water.

• Density of water = 1 g/mL

=> Mass = Volume × Density

=> Mass = 600×1

=> Mass = 600g

=> 1g = 0.001g

=> 600g = 600(0.001)

=> 0.6 kg

Hence, the required mass of water is 0.6kg.

Molality:-

= Moles of solute/Mass of solvent in kg

= 2/0.6

= 3.33 m

Thus, molality of the solution is 3.33 m.