Aconcentrated phosphoric acid solution is 85.5% h_3po_4 by mass and has a density of 1.69 g/ml at 25 degree c. what is the molarity of h_3po_4? a. 14.7 m b 0.166 c. 5.16 m d. 19.4 m e. 0.0516 m

a. 14.7 M

Explanation:

Given that :

is 85.5 % w/w in solution.  

It means that 85.5 g of the salt is present in 100 g of the solution.  

Mass of solution = 100 g  

Density = 1.69 g/mL

Volume of the solution = Mass / Density = 100 / 1.69 mL = 59.17 mL = 0.05917 L

Moles of can be calculated as:

Molar mass of =  97.994 g/mol

The formula for the calculation of moles is shown below:

Thus,

Moles = 0.8725 moles

Considering:

Molarity = moles/ Volume of solution = 0.8725 / 0.05917 = 14.7 M

it is the most commonly accepted one