0.222g of a divalent metal is deposited when a current of 0.45ampere is passed through a solution of its salt for 25min using appropriate electrodes calculate the relative atomic mass of the metal
an ampere is a Coulomb per second
... a Coulomb is 6.24 x 10^18 electrons
25 min * 60 s/min * 0.45 C/s * 6.24E18 e/C = ? electrons
find moles of electrons ... divide electrons by Avogadro's number
divide moles of electrons by two for moles of metal
... metal is divalent
divide grams of metal by moles of metal for relative atomic mass
Question
To calculate the relative atomic mass of the metal, we need to consider the following steps:
Step 1: Determine the amount of substance deposited.
To calculate the amount of substance deposited, we can use Faraday's law of electrolysis, which states:
Amount of substance (in moles) = (Current (in amperes) * Time (in seconds)) / (Faraday's constant)
In this case, the current is given as 0.45 ampere, and the time is 25 minutes. However, we need to convert the time from minutes to seconds:
Time (in seconds) = 25 minutes * 60 seconds/minute = 1500 seconds
The Faraday's constant is a conversion factor that tells us the amount of charge required to deposit one mole of a substance during electrolysis. Faraday's constant is approximately 96,500 coulombs.
So, the amount of substance deposited in moles is:
Amount of substance = (0.45 A * 1500 s) / 96500 C/mol
Step 2: Calculate the molar mass of the metal.
Since we know the amount of substance deposited in moles, we can calculate its molar mass by dividing the mass of the substance deposited (given as 0.222 g) by the amount of substance.
Molar mass = Mass of substance (in grams) / Amount of substance (in moles)
Step 3: Calculate the relative atomic mass (RAM).
The relative atomic mass is the average mass of an atom of an element compared to 1/12th the mass of a carbon-12 atom. It is obtained by comparing the molar mass of the element with the molar mass of carbon-12.
Relative atomic mass = (Molar mass of the metal / Molar mass of carbon-12) * 12
By following these steps, we can calculate the relative atomic mass of the metal.