Respuesta :
Answer : The chemical formula of a compound is, [tex]Ga_2O_3[/tex]
Solution : Â Given,
Mass of gallium = 1.25 g
Mass of gallium oxide = 1.68 g
Mass of oxygen = Mass of gallium oxide - Mass of gallium
Mass of oxygen = 1.68 - 1.25 = 0.43 g
Molar mass of Ga = 69.72 g/mole
Molar mass of O = 16 g/mole
Step 1 : convert given masses into moles.
Moles of Ga = [tex]\frac{\text{ given mass of Ga}}{\text{ molar mass of Ga}}= \frac{1.25g}{69.72g/mole}=0.0179moles[/tex]
Moles of O = [tex]\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{0.43g}{16g/mole}=0.027moles[/tex]
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For Ga = [tex]\frac{0.0179}{0.0179}=1[/tex]
For O = [tex]\frac{0.027}{0.0179}=1.5[/tex]
The ratio of Ga : O = 1 : 1.5
To make in whole number we multiple ratio by 2, we get:
The ratio of Ga : O = 2 : 3
The mole ratio of the element is represented by subscripts in empirical formula.
The Empirical formula = [tex]Ga_2O_3[/tex]
The empirical formula weight = 2(69.72) + 3(16) = 187.44 gram/eq
Now we have to calculate the molecular formula of the compound.
Formula used :
[tex]n=\frac{\text{Molecular formula}}{\text{Empirical formula weight}}[/tex]
[tex]n=\frac{187.44}{187.44}=1[/tex]
Molecular formula = [tex](Ga_2O_3)_n=(Ga_2O_3)_1=Ga_2O_3[/tex]
Therefore, the chemical of the compound is, [tex]Ga_2O_3[/tex]
