How many moles of protons are present in 35.0 ml of a 4.70 m solution of nitric acid?

Nitric acid is a strong acid, and so is completely dissociated into H+ and NO3- ions. So, the concentration of H+ is (conceptually) 4.60 mol H+/L. So, the number of moles of protons in this solution is: 
4.670 mol H+ /L X 0.0350 L = 0.1645 mol H+
The answer in this question is 0.1645 mol H+

Density and pressure

Answernon electrolyte;