How many minutes will it take to plate out 2.19 g of chromium metal from a solution of cr3+cr3+ using a current of 55.2 amps in an electrolyte cell?

Answer : The time it take to plate out will be, 3.69 minutes.

Explanation :

First we have to calculate the moles of Cr.

Molar mass of Cr = 51.9 g/mol

The cathode half-reaction is,

From this we conclude that,

The number of electrons (n)  in the reaction are 3.

The quantity of charge required for the reduction of 1 mole of =

The quantity of charge required for the reduction of 0.0423 mole of =

Now we have to calculate the time taken.

We know that,

Thus, the time it take to plate out will be, 3.69 minutes.

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.