Question

concentrated HCL is 38% by mass. what is the molarity of this solution if d=1.19g/cm^3? what volume of concentrated HCL is required to make 500ml of 0.1 M HCL?​

Answer 1

The molarity of HCl solution is 12.39 M and 4.04 mL of concentrated HCl solution is required to make the desired solution.

Explanation:

Given values:

38% HCl by mass

This means that 38 g of HCl is present in 100 g of solution

Density is defined as the ratio of mass and volume of a substance.

$\text{Density}=\frac{\text{Mass}}{\text{Volume}}$ ...(1)

Mass of solution = 100 g

Density of water = 1.19 g/mL

Putting values in equation 1, we get:

$1.19g/mL=\frac{100g}{\text{Volume of solution}}\\\\\text{Volume of solution}=\frac{100g}{1.19g/mL}=84.03mL$

Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:

$\text{Molarity of solution}=\frac{\text{Given mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (mL)}}$ ...(2)

We are given:

Given mass of HCl = 38 g

Molar mass of HCl = 36.5 g/mol

Volume of the solution = 84.03 mL

Putting values in equation 2, we get:

$\text{Molarity of solution}=\frac{38\times 1000}{36.5\times 84.03}\\\\\text{Molarity of solution}=12.39M$

To calculate the volume of stock solution needed, the formula used is:

$C_1V_1=C_2V_2$ ...(3)

where,

$C_1\text{ and }V_1$ are the concentration and volume of stock solution.

$C_2\text{ and }V_2$ are the concentration and volume of diluted solution.

$C_1=12.39\\V_1=?mL\\C_2=0.1M\\V_2=500mL$

Putting values in equation 3, we get:

$12.39\times V_1=0.1\times 500\\\\V_1=\frac{0.1\times 500}{12.39}\\\\V_1=4.04mL$

Learn more:

https://brainly.in/question/5772375

https://brainly.in/question/4913272