Molar mass
HNO₃ = 63.02 g/mol
N₂O = 44.013 g/mol
The balanced equation is :
4 Zn + 10 HNO₃ = 4 Zn(NO₃)₂ + N₂O + 5 H₂O
10 * 63.02 g HNO₃-----------> 44.013 g N₂O
? HNO₃ -----------------> 8.75 g N₂O
Mass HNO₃ = 8.75 * 10 * 63.02 / 44.013
Mass HNO₃ = 125 g
hope this helps!