Calculate the pH of the solution

Question

A chemist dissolves 836. of pure nitric acid in enough water to make up 350. mL of solution. Calculate the pH of the solution. Round your answer to 3 significant decimal places. 

Answer 1

Units are so important. 836 what of pure nitric acid? 836 g, mg, ul, ?

It can't be mls because then you couldn't have a final volume of 350 ml.

If it is grams, then we need the density of the nitric acid.