а) 39+14+16*3= 53+48=101
б) 23+14+32+16*4=69+64=133
3Hg(NO3)2+2H3PO4=Hg3(PO4)2+6HNO3
3Hg(2+)+6NO3(-)+6H(+)+2PO4(3-)=Hg3(PO4)2+6H(+)+6NO3(-)
3Hg(2+)+2PO4(3-)=Hg3(PO4)2
MgSO4 + 2NaOH -> Mg(OH)2+Na2SO4
Mg(+2)+SO4(-2)+2Na(+)+2OH(-) -> Mg(OH)2+2Na(+)+SO4(-2)
Mg(+2)+2OH(-)->Mg(OH)2
CH3OH+CHOOH=СHOOH3C+H2O
n CH3OH=9.2/32=0.2875 моль
n CHOOH=7.2/46=0.1565 моль
n СHOOH3C=0.1565 моль
m СHOOH3C=0.1565*60=9.39г