Question

What is the molarity of a solution that is 26.0% by mass in phosphoric acid, H3PO4, and that has a density of 1.155 g/mL?

Answer 1

Answer: The molarity of a solution that is 26.0% by mass in phosphoric acid is 3.06 M

Step-by-step explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.

`Molarity=(n* 1000)/(V_s)`

n = moles of solute

`V_s` =volume of solution in ml

Given : 26.0 g of phosphoric acid in 100 g of solution.

To calculate the moles, we use the equation:

`\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}=(26.0g)/(98g/mol)=0.265moles`

Volume of solution =
`\frac{\text {Mass of solution}}{\text {Density of solution}}=(100g)/(1.155g/ml)=86.6ml`

`Molarity=(0.265* 1000)/(86.6ml)=3.06M`

Molarity of a solution that is 26.0% by mass in phosphoric acid is 3.06 M