[r]
Trang 1em viet phuong trinh dien ly nhe
NaOH > Na(+) + OH(-)
0.125 0.375 0.125
KOH > K(+) + OH(-)
0.375 0.375 0.375
so mol OH(-) co trong dung dich la 0.125+0.375=0.5 mol dat T= so mol OH(-)/ so mol H3PO4 =0.5/0.2=2.5
nen se xay ra 2 phan ung sau:
2OH(-) + H3PO4 -> HPO4(2-) + 2H2O
2X X X
3OH(-) + H3PO4 -> PO4(3-) + 3H2O
3Y Y Y
TA CO HE PHUONG TRINH : 2X+3Y=0.5, X+Y =0.2 ->X= Y=0.1(MOL)
KHI CO CAN DUNG DICH KHOI LUONG MUOI BANG TONG KHOI LUONG CAC ION CO TRONG DUNG DICH NEN TA CO KHOI LUONG MUOI NHU SAU:
m= m(Na+) +m (k+) +m(HPO4(2-))+ m
(PO4(3-))=23.0.125 +39.0.375 +96.0.1 +95.0.1=36.6 (GAM)
THẦY GIÀU _GIA SƯ LUYỆN THI ĐẠI HỌC