Question

Given the two half-reactions, what must be done in the next step before the reaction can be balanced? Au3+ --> Au I- --> I2 Show the number of electrons being lost or gained. Make sure that the charges are balanced. List the atoms that need to be balanced.

Answer 1

A: Show the number of electrons being lost or gained.

Step-by-step explanation:

Answer 2

The balance equation is

`2Au^(+3) + 6I^(-)` →
`2Au + 3I_(2)`

Step-by-step explanation:

first, we have to make sure that the atoms are balanced

`Au^(+3)` →
`Au^{}`

`2I^(-)` →
`I_(2)`

then we proceed to balance charges of each half-reaction

`Au^(+3) + 3e^(-)` →
`Au^{}`

`2I^(-)` →
`I_(2)`
`+ 2e^(-)`

Now we multiply the half-reactions to match the number of electrons in each one

(
`Au^(+3) + 3e^(-)` →
`Au^{}`)x2

(
`2I^(-)` →
`I_(2)`
`+ 2e^(-)`)x3

and now we do the sum of the half-reactions

2
`Au^(+3) + 6e^(-)` → 2
`Au^{}`

`6I^(-)` → 3
`I_(2)`
`+ 6e^(-)`

`2Au^(+3) + 6I^(-)` →
`2Au + 3I_(2)`

note: the only atom that needed to be balanced was I