Respuesta :
moles = mass / molar mass
moles P = 0.422 g / 30.97 g/mol = 0.01363 mol
moles O = (0.967 g - 0.422g) / 16.00 g/mol = 0.03406 moles
So ratio moles P : moles O
= 0.01363 mol : 0.03406 mol
Divide each number in the ratio by the smallest number
(0.01363 / 0.01363) : (0.03406 / 0.01363)
= 1 : 2.5
The empirical formula needs to be the smallest whole number ratio of atoms in the molecules. Since you have a non-whole number, multiply the ratio by the smallest number needed to make both number whole numbers. In this case x 2
2 x (1 : 2.5)
= 2 : 5
moles P = 0.422 g / 30.97 g/mol = 0.01363 mol
moles O = (0.967 g - 0.422g) / 16.00 g/mol = 0.03406 moles
So ratio moles P : moles O
= 0.01363 mol : 0.03406 mol
Divide each number in the ratio by the smallest number
(0.01363 / 0.01363) : (0.03406 / 0.01363)
= 1 : 2.5
The empirical formula needs to be the smallest whole number ratio of atoms in the molecules. Since you have a non-whole number, multiply the ratio by the smallest number needed to make both number whole numbers. In this case x 2
2 x (1 : 2.5)
= 2 : 5
Answer :
(a) The empirical formula of a compound is, [tex]P_2O_5[/tex]
(b) The balanced chemical equation will be:
[tex]P_4+5O_2\rightarrow 2P_2O_5[/tex]
Solution : Given,
Mass of phosphorus = 0.422 g
Mass of white oxide = 0.967 g
Molar mass of phosphorus = 31 g/mole
Molar mass of oxygen = 16 g/mole
First we have to calculate the mass of oxygen.
Mass of oxygen = Mass of white oxide - Mass of phosphorus
Mass of oxygen = 0.967 - 0.422
Mass of oxygen = 0.545 g
Now convert given masses into moles.
Moles of P = [tex]\frac{\text{ given mass of P}}{\text{ molar mass of P}}= \frac{0.422g}{31g/mole}=0.0136moles[/tex]
Moles of O = [tex]\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{0.545g}{16g/mole}=0.0341moles[/tex]
For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For P = [tex]\frac{0.0136}{0.0136}=1[/tex]
For O = [tex]\frac{0.0341}{0.0136}=2.5[/tex]
The ratio of P : O = 1 : 2.5
To make this ratio in a whole number we multiple ratio by 2, we get:
The ratio of P : O = 2 : 5
The mole ratio of the element is represented by subscripts in empirical formula.
The Empirical formula = [tex]P_2O_5[/tex]
The balanced chemical equation will be:
[tex]P_4+5O_2\rightarrow 2P_2O_5[/tex]
