Question

The density of 1M solution of NaCl is 2.5g/ml. Find molality of the solution​

Answer 1

Answer:

0.1005

Explanation:

molarity: no of moles of solute in 1 L of solution

0.1M NaCl means in 1 L of NaCl solution there is

0.1 mol NaCl

molar mass of NaCl=58.5g/mol

mass=moles×molar mass=58.5×0.2=5.85g

this is mass of solute

we assumed there is 1L of sulution

density=m/v of solution is given mass of solution is 2.5=mass/1000ml

mass=2500g of solution

mass=5.85g solute

solute +solvent =solution

solvent=1000-5.85=994.15g

molality=n/mass of solvent in kg

=0.1/994.15/1000

0.1005 molal