14.5 cell EMF & direction of change Flashcards
1
Q
what does a positive E cell indicate?
A
reaction is spontaneous & feasible
2
Q
which electrode is oxidised? what is its relative Emf value to the other?
A
left hand side (more negative)
3
Q
which electrode is reduced? what is its relative Emf value to the other?
A
right hand side (more positive)
4
Q
explain the trend of a standard electrode potential series as it becomes more negative.
A
- more tendency to oxidise
- stronger reducing agents
5
Q
explain the trend of a standard electrode potential series as it becomes more positive.
A
- greater tendency to reduce
- stronger oxidising agent
6
Q
what are the 3 reasons that reaction might not be feasible?
A
1- high Ea
2- reaction occurs slowly
3- non-standard conditions
7
Q
in spontaneous direction, is electrode potentials exothermic or endothermic?
A
exothermic
8
Q
how does increasing temperature changes Ecell value?
A
- increase temperature favours endothermic reaction & shifts equilibrium backwards
- smaller Ecell value
