First, we need to find the amount in moles of each substance. WE have the mass for each so we use the formula:
n = m/Mn=mM
Where nn is the amount of the substance in moles, mm is the mass of the substance, and MM is the molar mass or molecular mass of the substance, which we can find by looking at the atomic mass on a periodic table so:
n("Cu") = (8.882g)/(63.546gmol^-1) = 0.139772763moln(Cu)=8.882g63.546gmol−1=0.139772763mol
and:
n(O) = (10g-8.882g)/(15.9994gmol^-1) = 0.06987762041moln(O)=10g−8.882g15.9994gmol−1=0.06987762041mol
Now we find the ratio of the copper and oxygen by dividing both values by the lowest value:
Cu:O = (0.139772763mol)/(0.06987762041mol):(0.06987762041mol)/(0.06987762041mol)Cu:O=0.139772763mol0.06987762041mol:0.06987762041mol0.06987762041mol
= 1.999535219 : 1=1.999535219:1
The value of 1.999535219 can be rounded to 4 significant figures to get a ratio of 2:12:1, as the figures in the question are given to 4 s.f.
From this ratio we can get the empirical formula of Cu_2OCu2O
