M.H2O = 2*1+16 = 18 g/mol
18g .................. 2g H
m g ................... 10g H
= 90 g apa
H2SO4 = 2*1+32+4*16 = 98 g/mol
nr.moli = m/M => m = nr.moli*M
= 5*98 = 490 g (md)
ms = md+m.apa = 490+90 = 580 g sol.
c% = md*100/ms = 490*100/580 = 84,50%