NaOH+HNO3=NaNO3+H2O
c=md/ms*100
40=md/120 *100
md=120*40/100
md=48 g HNO3
Masa atomica NaOH=23+16+1=40 g
Masa atomica HNO3=1+14+48=63 g
40g NaOH............................63 g HNO3
x...........................................48 g HNO3
x=40*48/63
x=30,47 g NaOH