Question

calculate the volumes in milliters of a 0.220M LiOH solution that Will completely neutralize each of the following 40.5 ml of 0.220M H3po4 solution

Answer 1

Molarity is defined as the no.of moles of a certain substance in 1L of solution. Thus, given that the phosphoric acid solution is 0.22M, 1000mL of the solution will contain 0.22moles of the acid. So, we can say that in 40.5mL there will be (0.22moles/1000mL)x40.5mL = 0.00891moles.

The law of equivalence and conservation of mass give that for neutralizing a given no.of moles of an acid, that many moles of a base is necessary. The balanced equation for this reaction is H₃PO₄ + 3LiOH -----> Li₃PO₄ + 3H₂O. Thus, it can be observed that the acid and the base react in a 1:3 ratio. This gives that 3x0.00891moles of LiOH is required to completely neutralize 0.00891moles of the acid.

Rearraging the previous equation to now calculate volume of LiOH, we get 0.02673 = (0.22/1000) x Volume. This gives the volume of base required as 0.02673/0.00022 = 121.5mL.

Thus, we can say that 121.5mL of 0.22M LiOH is required to completely neutralize 40.5mL of 0.22M phosphoric acid.