Vitamin C (FW =176.12 g- mol\'1) is found in many natural sources, especially in

Question

Vitamin C (FW =176.12 g- mol'1) is found in many natural sources, especially in citrus fruits. Vitamin C is a compound that is made up of carbon, hydrogen and oxygen atoms. When 1.000 g sample of Vitamin C is burned in a combustion apparatus, the following data is obtained. Using the data provided, calculate the masses of carbon, hydrogen, and oxygen in the sample of Vitamin C. Next, calculate the moles of carbon, hydrogen, and oxygen in the sample. Finally, using the data that you have calculate above, determine the empirical and molecular formulas of Vitamin C. empirical formula molecular formula

Explanation / Answer

The mass of carbon dioxide increased = 85.35 - 83.85 = 1.5 grams

The combustion reaction of carbon is

C+ O2 --> CO2

So if 44 grams of co2 is produced then 12 grams of carbon is present

So mass of carbon in the sample = 12 X mass of CO2 / 44 = 0.408 grams

Mass of water = 37.96 - 37.55 = 0.41

H2 + 1/2O2 --> H2O

So if 18 grams of H2O is produced then 2 grams of hydrogen is present

So mass of hydrogen in the sample = 2 X mass of H2O / 18 = 0.0455 grams

Rest will be oxygen = 1 - (0.408 + 0.0455 ) = 0.546 grams

2)

Moles of Carbon = 0.408 / 12= 0.034 moles

Moles of hydrogen = 0.0455 / 1= 0.0455moles

Moles of oxygen = 0.546 / 16 = 0.034 moles

So molar ratio is C" H : O = 3 : 4 : 3

empirical formula = C3H4O3

Let molecular formula = n X emperical formula

SO 176.12 = n ( 12 X 3 + 4 + 3 X 16 ) = 88n

n = 2

molecular formula = C6H8O6

Related Questions

Navigate

• Browse (All)
• Browse V
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.