Answer:

0.012 mole of electron

Explanation:

From the question given above, the following data were obtained:

Time (t) = 90.6 minutes

Current (I) = 213.8 mA

Number of mole of electrons =?

Next, we shall convert 90.6 mins to seconds. This can be obtained as follow:

1 min = 60 s

Therefore,

90.6 mins = 90.6 × 60

90.6 mins = 5436 s

Next, we shall convert 213.8 mA to A. This can be obtained as follow:

1000 mA = 1 A

Therefore,

213.8 mA = 213.8 mA × 1 A / 1000 mA

213.8 mA = 0.2138 A

Next, we shall determine the quantity of electricity used in the process. This can be obtained as follow:

Time (t) = 5436 s

Current (I) = 0.2138 A

Quantity of electricity (Q) =?

Q = it

Q = 0.2138 × 5436

Q = 1162.2168 C

Next, the equation for the reaction.

Au⁺ + e —> Au

From the balanced equation above,

1 mole of electron was transferred.

Recall:

1 faraday = 96500 C = 1 e

Thus,

96500 C of electricity is needed to transfer 1 mole of electron.

Finally, we shall determine the number of mole electrons transferred by the application of 1162.2168 C of electricity. This can be obtained as follow:

96500 C of electricity is needed to transfer 1 mole of electron.

Therefore,

1162.2168 C of electricity will transfer = 1162.2168 / 96500 = 0.012 mole of electron

Thus, 0.012 mole of electron was transferred in the process.