2 Answers

The mass of silver deposited when a current of 10A…

Posted by: 601 views
CHEMISTRY

The mass of silver deposited when a current of 10A passed through a solution of silver salt for 4830s is A. 108.0g

B. 54. 0g

C. 27.0g

D. 13.5g

QUICK ANSWER…

B

SOLUTION…  

Quantity of electricity = current × time = 10 × 4830 = 48300 coulombs

Now silver ion is monovalent, this means:

1 faraday of electricity is required to deposit 1 mole of silver.

Or 1 faraday of electricity is required to deposit 108g of silver.

1 faraday = 96500 coulombs

So, if 96500 coulombs of electricity deposits 108g of silver,

Then, 48300 coulombs of electricity will deposit x g of silver.

also written this way:

96500 coulombs = 108g

48300 coulombs = x

Cross multiplying to find the value of x, we have:

x(96500) = 108(48300)

x = 108(48300)/96500 = 5216400/96500 = 54.056g

Now for the right answer to the above question:

  1. Option A is incorrect.
  2. Option B is correct.
  3. C is incorrect.
  4. D is not the correct answer.
RELATED!  A quantity of electricity liberates 3.6 g of silver from...

KEY-POINTS…

You may please note these/this:

  • Always remember that for a monovalent ion, 1 faraday is required to liberate or deposit 1 mole of the element, for a divalent ion, 2 faradays will be required to liberate or deposit 1 mole of the element, and for a trivalent ion, 3 faradays will be required to liberate or deposit 1 mole of the element.
  • Examples of monovalent ions are: hydrogen, hydroxide, sodium, silver, potassium, chlorine…
  • Examples of divalent ions are: calcium, lead, magnesium, oxygen, mercury, copper, tin…
  • Examples of trivalent ions are Aluminum, boron…

Use the questions and answers session to raise further questions and deal more on this topic…

You can also freely share this page with friends.

/ culled from 2017 JAMB-UTME Chemistry question 16 /

Answer Question