Question

36.5 percent HCl has density 1.20 g /ml.The molarity and molality are

Answer 1

Answer : The molarity and molality of the solution is, 12.0 mole/L and 15.7 mole/Kg respectively.

Solution : Given,

Density of solution = 1.20 g/ml

Molar mass of HCl (solute) = 36.5 g/mole

36.5% aqueous solution of HCl means that 36.5 gram of HCl is present in 100 g of solution.

Mass of HCl (solute) = 36.5 g

Mass of solution = 100 g

Mass of solvent = Mass of solution - Mass of solute = 100 - 36.5 = 63.5 g

First we have to calculate the volume of solution.

$\text{Volume of solution}=\frac{\text{Mass of solution}}{\text{Density of solution}}=\frac{100g}{1.20g/ml}=83.33ml$

Now we have to calculate the molarity of solution.

$Molarity=\frac{\text{Moles of solute}\times 1000}{\text{Molar mass of solute}\times \text{volume of solution}}=\frac{36.5g\times 1000}{36.5g/mole\times 83.33ml}=12.0mole/L$

Now we have to calculate the molality of the solution.

$Molality=\frac{\text{Moles of solute}\times 1000}{\text{Molar mass of solute}\times \text{Mass of solvent}}=\frac{36.5g\times 1000}{36.5g/mole\times 63.5g}=15.7mole/Kg$

Therefore, the molarity and molality of the solution is, 12.0 mole/L and 15.7 mole/Kg respectively.

Answer 2

Answer:12,15.7

Explanation: