Chemistry
Calculate the mass of silver deposited when a current of 2.6A is passed through a solution of a silver salt for 70minutes. (Ag=108;1faraday=96500C)
To calculate the mass of silver deposited, we need to use Faraday's law of electrolysis, which states that the amount of substance deposited or evolved during electrolysis is directly proportional to the quantity of electricity passed through the electrolyte.
The formula to calculate the mass of substance deposited is:
Mass (m) = (Z * I * t) / (n * F)
Where:
- Mass (m) is the mass of substance deposited (in grams).
- Z is the electrochemical equivalence of the substance, representing the number of moles of electrons involved in the reduction or oxidation of one mole of the substance. For silver (Ag), Z = 1 (as per its chemical equation).
- I is the current (in amperes) passing through the solution.
- t is the time (in seconds) for which the current flows.
- n is the number of electrons involved in the electrochemical reaction. For silver deposition, it is 1, as Ag+ ions are reduced to Ag atoms.
- F is Faraday's constant, which is 96500 C/mol e-.
First, let's convert the given time of 70 minutes into seconds:
Time (t) = 70 minutes * 60 seconds/minute
Next, substitute the given values into the formula:
Mass (m) = (1 * 2.6A * 70 minutes * 60 seconds/minute) / (1 * 96500 C/mol e-)
Simplifying the equation and converting minutes to seconds:
Mass (m) = (2.6A * 70 * 60s) / (96500)
Finally, calculate the mass of silver deposited by substituting the values:
Mass (m) = (2.6 * 70 * 60) / 96500
= 11.97 grams (approximately)
Therefore, the mass of silver deposited when a current of 2.6A is passed through the solution for 70 minutes is approximately 11.97 grams.