What is the percentage composition of copper, Cu, in Cu20?
A. 44%
B. 80%
C. 89%
D. 133%
I Choose C, Am I correct?
yes
88.82% which rounds to 89%
To determine the percentage composition of copper (Cu) in Cu2O, we need to calculate the molar mass of Cu2O and then determine the mass of copper (Cu) within that molar mass.
The molar mass of Cu2O can be calculated by adding the atomic masses of copper (Cu) and oxygen (O).
Cu: atomic mass = 63.55 g/mol
O: atomic mass = 16.00 g/mol
Molar mass of Cu2O = 2(Cu) + O = 2(63.55 g/mol) + 16.00 g/mol = 143.10 g/mol
Now, we need to determine the mass of copper (Cu) within one mole of Cu2O.
The mass of copper (Cu) is equal to the atomic mass of copper (Cu) times the number of copper atoms in one mole of Cu2O.
To find the number of copper atoms in one mole of Cu2O, we can use the subscripts from the chemical formula. In this case, the subscript of Cu is 2, indicating that there are two copper atoms in one mole of Cu2O.
Mass of copper (Cu) = atomic mass of Cu * number of Cu atoms
= 63.55 g/mol * 2
= 127.10 g
Finally, to determine the percentage composition of copper (Cu) in Cu2O, we divide the mass of copper (Cu) by the molar mass of Cu2O and multiply by 100.
Percentage composition of Cu in Cu2O = (mass of Cu / molar mass of Cu2O) * 100
= (127.10 g / 143.10 g/mol) * 100
≈ 88.81%
Therefore, the correct answer is C. 89%.