Chemistry Neutralization Concentration

Question

Consider the neutralization reaction

2HNO3(aq)+Ba(OH)2(aq)⟶2H2O(l)+Ba(NO3)2(aq)

A  sample of an unknown  solution required  of  for complete neutralization. What is the concentration of the  solution?

I would like help solving this, but I also need help understanding what to do and when. Thank you for your help :)

Answer 1

Hello, Jamie,

The balanced equation tells us we need twice the number of moles of nitric acid as the number of moles of barium hydroxide. If we are titrating the barium hydroxide, for example, we can take the number of ml HNO3 used to calculate the number of moles of HNO3 required for neutralization. [moles HNO3 = (Molar Mass of HNO3)*(liters used for titration). Convert ml to liters by dividing by 1000].

Once the moles HNO3 are calculated, divide by 2 to determine the moles of Ba(OH)2 were present in the titrated sample. We divide by two to reflect what the balanced equation told us: It takes 2 moles HNO3 for every one mole barium hydroxide. Once we have the moles, divide by the liters of the titrated sample. If 20ml of the Ba(OH)2 was titrated, divide the moles Ba(OH)2 by 0.020 liters to find molarity.

If, for example, it took 30 ml of a 0.5M solution to neutralize 50 ml of the Ba(OH)2.

Bob