A current of 2.50 A is passed through a solution containing Cu+2 ions for 4.00 hours. Calculate the mass of Cu atoms that form at the cathode.
Charge= current*time
Convert the charge in coulombs to number of electrons.
Since it takes two electrons per Cu+2 atom, divide the number of electrons by two, and you have the number of atoms of Cu. Change this to mass, either by mass/atom, or change to moles (avag number), then to mass.
14.5
To calculate the mass of Cu atoms that form at the cathode, you need to follow these steps:
1. Start by calculating the total charge passed through the solution.
Charge = current * time
In this case, the current is 2.50 A and the time is 4.00 hours. Convert the time to seconds by multiplying it by 3600 (since there are 3600 seconds in an hour).
Charge = 2.50 A * (4.00 hours * 3600 seconds/hour)
2. Convert the charge in coulombs to the number of electrons passed.
Each coulomb corresponds to 6.242 × 10^18 electrons. So, divide the charge value by the elementary charge.
Number of electrons = Charge / Elementary charge
Elementary charge = 1.602 × 10^-19 coulombs
3. Since each Cu+2 ion requires 2 electrons to form Cu atoms at the cathode, divide the number of electrons by 2 to get the number of Cu atoms formed.
4. Convert the number of Cu atoms to mass.
You have two options here:
a) Find the mass per atom of Cu and multiply it by the number of Cu atoms.
b) Convert the number of Cu atoms to moles using Avogadro's number (6.022 × 10^23 atoms/mole) and then convert moles to mass using the molar mass of Cu (63.55 g/mole).
You can choose whichever method you prefer.
Using the given information, follow these calculations to find the mass of Cu atoms formed:
1. Calculate the total charge passed through the solution:
Charge = 2.50 A * (4.00 hours * 3600 seconds/hour) = (2.50)(4.00)(3600) coulombs
2. Convert the charge to the number of electrons:
Number of electrons = (2.50)(4.00)(3600) / (1.602 × 10^-19) electrons
3. Divide the number of electrons by 2 to get the number of Cu atoms formed.
4. Convert the number of Cu atoms to mass:
Option a) Multiply the number of Cu atoms by the mass per atom of Cu.
Option b) Convert the number of Cu atoms to moles using Avogadro's number and then convert moles to mass using the molar mass of Cu.
Choose the appropriate method and perform the calculations to find the mass of Cu atoms formed at the cathode.