Question

equal moles of H2O and NaCl are present in a solution hence molality of NaCl is ​

Answer 1

a/c to question, equal moles of H2O and NaCl are present in a solution.

Let n moles of NaCl are present in n moles of H2O solution.

so, number of moles of NaCl(solute) = n

mass of water (solvent ) =number of moles of H2O × molar mass of H2O

= n × 18 = 18n grams [ as you know, molar mass of H2O = 18g/mol]

use formula, molality = number of mole of solute/mass of solvent in Kg

= n × 1000/(18n )

= 1000/18

= 55.55 molal

hence, molality of NaCl is 55.55m.