Answer
0.8000 g is the mass of oxygen that is combined with 3.1777g of metallic element X.
atomic mass of X= 63.54 amu
We see in the periodic table of elements that Cu ( cooper) is the element with the atomic mass 63.54 amu.
Work Step by Step
Based on the chemical formula of XO, note that XO contains one atom X for every one atom O.
1- First we are required ti find the mass of oxygen that i combined with metallic element X.
We are given the volume and density of oxygen that is used in this chemical reaction. We can find the mass of oxygen .
We know: d = $\frac{m}{v}$
By multiplying both sides with v we get an identical equation with this one: d x v = $\frac{m}{v}$ x v
m = d x v
Replace density and volume to find the volume of oxygen:
m = 0.6015L x 1.330 $\frac{g}{L}$
m = 0.8000 g
So we found out that 0.8000 g is the mass of oxygen that is combined with 3.1777g of metallic element X.
2- We have to find atomic mass of X.
Based on the chemical formula of XO, we notice that XO contains one atom X for every one atom O,
so in XO there is this ratio:
1 atom X : 1 atom O
atomic mass X : atomic mass O
replace atomic mass of O:
atomic mass X : 15.9994 amu O
We know as well that 3.1777g of X is combined with 0.8000 g of oxygen in XO.
So we have these ratios:
atomic mass X : 15.9994 amu O
3.1777g X : 0.8000 g O
By applying mathematical rule of three we can find atomic mass of X:
atomic mass of X = $\frac{3.1777g * 15.9994 amu}{0.8000 g}$
atomic mass of X= 63.538 amu
atomic mass of X= 63.54 amu
We see in the periodic table of elements that Cu ( cooper) is the element with the atomic mass 63.54 amu.
