Question

suppose you run electrolysis for 20.26 minutes at an average current of 146.1 milliamperes. how many coulombs pass through your electrolysis cell? How many electrons?

(1 COULOMB= 1 AMPERE*1 SECOND)

Answer 1

Formula to calculate no. of Coulombs is:

Coulombs = Current ( in Ampere) X Time (in seconds)

Step 1 : Unit conversion of time from minutes to seconds

1 minute = 60 seconds

so, 20.26 minutes =( 20.26 min)X(60 s)/(1 min) = 1215.6 s

so, time = 1215.6 s

Step 2 : unit conversion of current from mA to A

1mA = 1/1000 A

so, 146.1mA = 146.1/1000 = 0.1461 A

current = 0.1461 A

Step 3: To calculate Coulombs

Coulombs = current X time = 0.1461A X 1215.6s = 179.59916 C 179.6 C

So, 179.6 coulombs pass through the electrolysis cell.

Step 4 : to calculate no. of electrons

charge on 1 electron = 1.60217662 × 10^-19 coulombs/ electron

coulombs passing through the electrolysis cell = 179.6 Coulombs

so, no. of electrons = coulombs passing through the electrolysis cell / charge on 1 electron

no. of electrons = 179.6 Coulombs / (1.60217662 × 10^-19 coulombs/ electron)

no. of electrons = 112.0975 X 10¹⁹ = 1.12 X 10²¹

So, there are 1.12 X 10²¹ electrons passing through the electrolysis cell.