Question

if 40 g of naoh present in 100 g of water the Molality is​

Answer 1

Answer:

molality is

moles of solute

divided by

weight of solvent in kilograms

in this question, moles of solute will be 40/40=1

molecular weight of NaOH is 40

weight of solvent is 0.1 kilogram as given in question.

divide 1/0.1

10 molal answer

Answer 2

Given:

40 grams of NaOH is dissolved in 100 gram of water.

To find:

Molality of water?

Calculation:

Molality is defined as the ratio of moles of solute to the weight of solvent.

$Molality = \dfrac{moles \: of \: solute}{weight \: of \: solvent \: (in \: kg)}$

$\implies Molality = \dfrac{ \bigg( \dfrac{given \: mass}{molar \: mass} \bigg)}{weight \: of \: solvent}$

$\implies Molality = \dfrac{ \bigg( \dfrac{40}{40} \bigg)}{0.1}$

$\implies Molality = \dfrac{ 1}{0.1}$

$\implies Molality = 10$

So, molality of solution is 10 m.