To calculate the mass of copper and silver deposited by the same quantity of electricity, we need to use Faraday's laws of electrolysis. According to Faraday's first law of electrolysis, the mass of substance deposited or liberated at an electrode is directly proportional to the quantity of electricity passed through the electrolyte.
The formula to calculate the mass of a substance deposited is:
Mass = (Q * M) / (n * F)
Where: Mass = Mass of substance deposited Q = Quantity of electricity passed in Coulombs M = Molar mass of the substance n = Number of electrons transferred in the reaction F = Faraday's constant (approximately 96,485 C/mol)
Given: Q = Quantity of electricity passed Volume of oxygen liberated = 450 cm³ Temperature = Standard Temperature and Pressure (STP), which is 273 K and 1 atm 1 mole of gas occupies 22.4 L at STP
First, we need to calculate the number of moles of oxygen gas liberated:
Number of moles of oxygen = Volume of oxygen / Molar volume at STP Number of moles of oxygen = 450 cm³ / 22.4 L/mol Number of moles of oxygen = 0.02004 mol
Since the volume of oxygen liberated is directly proportional to the quantity of electricity passed, the number of moles of copper and silver deposited will be the same as well.
Now, we can calculate the mass of copper and silver using the formula mentioned earlier.
For copper: Molar mass of copper (Cu) = 63.55 g/mol n = 2 (Copper ions gain 2 electrons to form copper metal)
Mass of copper = (Q * M) / (n * F) Mass of copper = (Q * 63.55 g/mol) / (2 * 96,485 C/mol)
For silver: Molar mass of silver (Ag) = 107.87 g/mol n = 1 (Silver ions gain 1 electron to form silver metal)
Mass of silver = (Q * M) / (n * F) Mass of silver = (Q * 107.87 g/mol) / (1 * 96,485 C/mol)
Please provide the value of Q (Quantity of electricity passed) in Coulombs to calculate the mass of copper and silver more accurately.