commercially available concerated HCl contains 38% by mass .find out 1. molarity of the solution if the density is 1.19g/cm³

2. what volume of concentrated HCl is required to make 1 litre of 0.10 molar HCl

A 38% by mass solution of HCl means that 38 g of HCl is present in 62g of water, thereby making the total mass of solution equal to 100g. The molar mass of HCl is 36.5g. Therefore, the number of moles of HCl that are present in 38g of HCl are

= mass of HCl / molar mass of HCl
= 38 / 36.5 = 1.041

The molality of a solution is defined as the number of moles of solute present per kg of the solvent. Here, the solvent is water and its mass is 62g. So molality
= number of moles of solute / mass of solvent (in Kg)
= (1.041 / 62) X 1000
= 16.791 m

Thus the molality of the solution is 16.791 m.

For molarity, we need to calculate the volume of the solution. We know that

volume of solution = mass / density
Mass of solution = 100 g

Thus volume of 100g 38% solution of HCl
= 100 / 1.19
= 84.03 mL

Now molarity
= number of moles of solute / volume of solution (in litres)
So molarity of HCl solution = (1.041 X 1000) / 84.03
= 12.38 M
(2) Final molarity to be prepared, M₂ = 0.10 M 
Volume, V₂ = 1 L
Molarity, M₁ = 12.38 M
Volume required, V₁ = ?
As we know M₁V₁ = M₂V₂
12.38 X V₁ = 0.1 X 1
V₁ = 0.1 / 12.38
= 0.0081 mL
Volume required = 0.0081 mL