1. 2018 Na2S2O35H2OM=248gmol -1
1 Ksp(BaSO
4)=1.1 10 -10Ksp(BaS2O
3)=4.1 10 - 5
H
2SO
4BaCl2 Na2CO
3 H
2O
2
___________ __________
___________ ___________
2 K2Cr2O7
1.2000g __________
100mL_________ ____________
0.00950 mol-1 K2Cr2O7 20.00mL KI Cr2O
2-
7
+6I -+14H+===3I2+2Cr3++7H2O I2+2S2O
2-
3===S
4O
2-
6+2I -
__________ 3
24.80mL _________% 1
1
S2O
2-
3+2H+===SO2+S+H2O
100mL
Cr2O
2-
73I 26S2O
2-
3 100mL