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

Answer:

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

Explanation:

Answer 2

Answer:

The balance equation is

$2Au^{+3} + 6I^{-}$ → $2Au + 3I_{2}$

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