Respuesta :
Answer: The molecular formula will be [tex]C_2H_4O_2[/tex]
Explanation:
If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
Mass of C= 40.01 g
Mass of H = 6.70 g
Mass of O = 100-(40.01+ 6.70) = 53.29 g
Step 1 : convert given masses into moles.
Moles of C =[tex]\frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{40.01g}{12g/mole}=3.33moles[/tex]
Moles of H =[tex]\frac{\text{ given mass of H}}{\text{ molar mass of H}}= \frac{6.70g}{1g/mole}=6.70moles[/tex]
Moles of O =[tex]\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{53.29g}{16g/mole}=3.33moles[/tex]
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For C = [tex]\frac{3.33}{3.33}=1[/tex]
For H = [tex]\frac{6.70}{3.33}=2[/tex]
For O =[tex]\frac{3.33}{3.33}=1[/tex]
The ratio of C : H: O= 1: 2: 1
Hence the empirical formula is [tex]CH_2O[/tex]
The empirical weight of [tex]CH_2O[/tex] = 1(12)+2(1)+1(16)= 30 g.
The molecular weight = 60 g/mole
Now we have to calculate the molecular formula.
[tex]n=\frac{\text{Molecular weight }}{\text{Equivalent weight}}=\frac{60}{30}=2[/tex]
The molecular formula will be=[tex]2\times CH_2O=C_2H_4O_2[/tex]
The molecular formula will be C₂H₄O₂. This can be described using empiricial formula first.
Determination of molecular formula:
The mass of each element is equal to the percentage given.
Mass of C= 40.01 g
Mass of H = 6.70 g
Mass of O = 100-(40.01+ 6.70) = 53.29 g
Conversion of masses into moles:
Moles of C = 40.01 / 12 = 3.33 moles
Moles of H = 6.70 / 1 = 6.70 moles
Moles of O = 53.29 / 16 = 3.33 moles
Dividing each with lowest moles:
For C = 3.33 / 3.33 = 1
For H = 6.70/ 3.33 = 2
For O = 3.33/ 3.33 = 1
The ratio of C : H: O= 1: 2: 1
Hence, the empirical formula is CH₂O
The empirical weight of CH₂O = 1(12)+2(1)+1(16)= 30 g.
The molecular weight = 60 g/mole
For molecular formula:
n= Molecular weight / Equivalent weight
n= 60/30 = 2
The molecular formula will be= 2 * CH₂O = C₂H₄O₂
Find more information about Molecular formulas here:
brainly.com/question/1603500
