Answer: The empirical formula is [tex]H_3PO_4[/tex]
Explanation:
Given:
Mass of H = 0.3086 g
Mass of P = 3.161 g
Mass of O = 6.531 g
Step 1 : convert given masses into moles.
Moles of H=[tex]\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{0.3086g}{1g/mole}=0.309moles[/tex]
Moles of P=[tex]\frac{\text{ given mass of P}}{\text{ molar mass of P}}= \frac{3.161g}{31g/mole}=0.102moles[/tex]
Moles of O =[tex]\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{6.531g}{16g/mole}=0.408moles[/tex]
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For H= [tex]\frac{0.309}{0.102}=3[/tex]
For P= [tex]\frac{0.102}{0.102}=1[/tex]
For O =[tex]\frac{0.408}{0.102}=4[/tex]
The ratio of H:P:O= 3: 1: 4
Hence the empirical formula is [tex]H_3PO_4[/tex]
