J.R. S. answered 01/10/22
Ph.D. University Professor with 10+ years Tutoring Experience
Molar mass HNO3 = 63.0 g / mol
moles HNO3 present = 7.48 g x 1 mol / 63.0 g = 0.119 mols
moles HNO3 per liter = 0.119 mols / 125 mls x 1000 mls / L = 0.952 mols/liter
HNO3 is a strong acid and will ionize completely to produce H+ and NO3-
[H+] = 0.952 mols/liter
[NO3-] = 0.952 mols/liter