Cp=md/ms*100==>md=Cp*ms/100=10*500/100=50g Na2CO3
MNa2CO3*10H2O = 2ANa+AC+3AO +10(2AH+AO)= 2*23+12+3*16+10(2*1+16)=106+180=286g/mol (106g Na2CO3 anhidra si 180g apa)
286g Na2CO3*10H2O................................106g Na2CO3
x=134,9g..........................................................50g Na2CO3