Question

5.85g of NaCl is dissolved in 1kg of water, calculate boiling point of saolution . given kb=0.52Kkg/mol, molar mass of nacl= 58.5g/mol , boiling point of water = 373.15K

Answer 1

Answer:

373.202 K

Explanation:

Given :

5.85 g of NaCl dissolved in 1 kg of water .

No. of moles = 5.85 / 58.5 = 0.1 moles

We have also given :

K_b = 0.52 K kg mol⁻¹

Boiling point of water = 373.15 K

We are asked to find :

Boiling point of solution :

We know :

Δ T_b = i K_b × m

Here m is molality = No. of moles of solute / Mass of solvent.

We are considering Van't Hoff factor i.e. i = 1

= > m = 0.1 / 1 = 0.1 m

= > Δ T_b = 1 × 0.52 × 0.1 K

= >  Δ T_b = 0.052 K

Therefore , boiling point of solution is ( 373.15 + 0.052 ) K = 373.202 K

Answer 2

Explanation:

373.202 K

this is the boiling point of the solution.