Answer:
12 M
Explanation:
The reaction between HNO₃ and KOH is:
First we calculate how many KOH moles reacted with the diluted HNO₃ sample, using the given volume and concentration:
As 1 KOH mol reacts with 1 HNO₃ mol, in 25 mL of the diluted HNO₃ solution there are 30 HNO₃ mmoles.
With that information in mind we can calculate the HNO₃ concentration in the diluted solution:
Finally we can use the C₁V₁=C₂V₂ formula to calculate the concentration of the original solution: