It would most likely be a observation or hypothesis
Answer:
Copper ions are reduced into copper atoms.
Cu²⁺₍aq₎ + 2e⁻ → Cu₍s₎
Explanation:
During electrolysis, the positive H⁺ and Cu⁺ ions move to the negative cathode and negative OH⁻ and Cl⁻ ions move to the positive anode.
At cathode, copper ions are preferentially discharged due to the low electromotive force required to discharge them compared to the hydrogen ion. The copper ions gain the two electrons lost by the chloride ions when the are discharged. (2 Cl⁻₍aq₎ → Cl₂₍g₎ + 2e⁻)
Thus the half equation is as follows:
Cu²⁺₍aq₎ + 2e⁻ → Cu₍s₎
The molar mass should be 14.898g/mol.
I used the equation 100gx(1/xg/mol)x(1mol/2mol)x(16g/mol+x)/1)=103.7 and solve for x.
I found that equation using stoichiometry and the equation 2m+1/2O2-->m2O
The molar mass of the metal I set to x and the molar mass of the metal oxide is 16+x.