Question

What is the concentration of 60 mL of H3PO4 if it is neutralized by 225 mL of 2 M Ba(OH)2?

Answer 1

7.5 M is the concentration of 60 ml of H3PO4 if it is neutralized by 225 ml of 2 M Ba(OH)2.

Explanation:

Data given:

volume of phosphoric acid, Vacid =60 ml

volume of barium hydroxide, Vbase = 225 ml

molarity of barium hydroxide, Mbase = 2M

Molarity of phosphoric acid, Macid =?

the formula for titration is used as:

Macid x Vacid = Mbase x Vbase

rearranging the equation to get Macid

Macid = $\frac{Mbase x Vbase}{Vacid}$

Macid =$\frac{225 X 2}{60}$

Macid = 7.5 M

the concentration of the phosphoric acid is 7.5 M and the volume is 60 ml. Thus 7.5 M solution of phosphoric acid is used to neutralize the barium hydroxide solution of 2M.

Answer 2

Answer:

= 5 M

Explanation:

2H3PO4 + 3Ba(OH)2 ----> Ba3(PO4)2 + 3H2O

moles Ba(OH)2 = molarity x litres

= 2 M x 0.225 L

= 0.45 mol

3 moles Ba(OH)2 react with 2 moles H2SO4

So moles H2SO4 = 2/3 x moles Ba(OH)2

= 0.3 mol

molarity = moles / litres

= 0.3 mol / 0.06 L

=5M