Question

how long a current of 3 ampere has to be passed through a solute agno3 to coat q metal 80cm square with a 0.005mm thick layer density of silver is 10.5 gm/cm square

Answer 1

Answer of Yr question is given over here....

Answer 2

Answer: 125 seconds

Explanation:-

$AgNO_3\rightarrow Ag^++NO_3^-$

Volume of silver to be deposited =$Area\times Thickness=80cm^2\times 0.0005cm=0.04cm^3$   (1mm=0.1 cm)

Density of silver= $10.5g/cm^3$

Mass of silver to be deposited=$Density\times Volume=10.5\times 0.04=0.42g$

$Ag^++e^-\rightarrow Ag$

108 g of Ag is deposited by =96500 Coloumb of electricity

0.42 g of Ag is deposited by=$\frac{96500}{108}\times 0.42=375.2C$ of electricity

$Q=I\times t$

where Q= quantity of electricity in coloumbs

I = current in amperes = 3 A

t= time in seconds = ?

$375.2C=3A\times t$

$t=125s$