3.2 Redox Reactions Flashcards
1
Q
What does Cr2O7 2- go to?
A
Cr3+
2
Q
What does MnO4- go to?
A
Mn2+
3
Q
What does S2O3 2- go to?
A
S4O6 2-
4
Q
What does H2O2 go to?
A
H2O or O2
5
Q
What does NO3 - go to?
A
NO or NO2
6
Q
What does SO4 2- go to?
A
SO2
7
Q
What does C2O4 2- go to?
A
CO2
8
Q
What does Fe2+ go to?
A
Fe3+
9
Q
State and explain how the voltmeter value would change if Cr3+ ion conc increased whilst Cr2O7^2- unchanged
A
- reading smaller
- increase in Cr3+ ions shifts equilibria left
10
Q
Half equation for acidified dichromate ions acting as oxidising agent
A
Cr2O7 2- + 14H+ + 6e- —> 2Cr3+ + 7H2O
11
Q
Equation for redox reaction between Cu2+ and I-
A
2Cu2+ + 4I- —> 2CuI + I2
12
Q
Explain the observations of the reaction between Cu2+ and I-
A
- copper is reduced and iodide oxidised
- brown ppt forms
13
Q
Colour change in the redox reaction when iodine reacts with thiosulfate ions
A
Brown to colourless
14
Q
What indicator is used for the reaction between iodine and thiosulfate
A
Starch
