solution for the equation 0.222g of a divalent metal is deposited when a current of 0.45 ampere is passed through a solution of it salt for 25 minutes using appropriate electrode calculate the relative atomic mass of the metal (if 96500c)
4 volts
Coulombs = amperes x seconds
C = 0.45 A x25 min x (60 sec/min) = 675
You know that 96,485 C will deposit one equivalent weight (atomic mass/2) of the divalent metal; therefore,
(atomic mass/2) x (675/96,485) = 0.222
atomic mass = 0.222*2*96,485/675 = ?
To calculate the relative atomic mass of the metal, we need to know the number of moles of metal that have been deposited. We can obtain this information by using Faraday's law of electrolysis.
Faraday's law states that the amount of substance deposited during electrolysis is directly proportional to the quantity of electricity passed through the solution. The formula is as follows:
Amount of substance (in moles) = (Quantity of electricity (in coulombs) / Faraday's constant) / Valency of the metal
Given:
Quantity of electricity (Q) = 0.45 A * 25 min * 60 s = 675 C (converting minutes to seconds)
Faraday's constant (F) = 96500 C/mol
Valency of the metal = 2 (divalent metal)
Applying the formula for moles:
Amount of substance (in moles) = (675 C / 96500 C/mol) / 2
Simplifying the equation:
Amount of substance (in moles) = 0.00350 mol
Now, we can calculate the relative atomic mass of the metal. The relative atomic mass is the mass of one mole of the metal. We can determine the mass using the formula:
Relative atomic mass = Mass of substance (in grams) / Amount of substance (in moles)
Given that 0.222g of the metal has been deposited:
Relative atomic mass = 0.222g / 0.00350 mol
Calculating the relative atomic mass:
Relative atomic mass ≈ 63.4 g/mol
Therefore, the relative atomic mass of the metal is approximately 63.4 g/mol.