0.60g of a gaseous hydrocarbon E when completely burnt in oxygen gave 1.76g of carbon dioxide.

WHAT IS THE EMPIRICAL FORMULA OF E?

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To determine the empirical formula of the gaseous hydrocarbon E, we need to calculate the mole ratio between the given masses of carbon and hydrogen.

1. Start by calculating the number of moles of carbon dioxide (CO2) produced:
- The molar mass of carbon dioxide (CO2) is 44 g/mol.
- Divide the given mass of carbon dioxide (1.76g) by its molar mass (44 g/mol):
1.76g / 44 g/mol = 0.04 mol CO2

2. Since hydrocarbons only contain carbon and hydrogen, we know that all the carbon atoms in the hydrocarbon are converted to carbon dioxide. Therefore, we can equate the number of moles of carbon dioxide to the number of moles of carbon in the hydrocarbon.

3. Calculate the number of moles of carbon:
- Multiply the number of moles of carbon dioxide (0.04 mol CO2) with the mole ratio of carbon to carbon dioxide, which is 1:1:
0.04 mol CO2 * (1 mol C / 1 mol CO2) = 0.04 mol C

4. Now, we need to determine the number of moles of hydrogen.
- To do this, we need to find the excess mass in the hydrocarbon, which is the difference between the original mass of the hydrocarbon and the mass of carbon dioxide produced:
Excess mass = Mass of hydrocarbon - Mass of carbon dioxide produced
Excess mass = 0.60g - 1.76g = -1.16g

5. The negative value for the excess mass indicates that there was not enough mass of the hydrocarbon to produce all the carbon dioxide. Therefore, hydrogen is present in the compound.

6. Convert the excess mass of hydrogen to moles.
- The molar mass of hydrogen (H2) is 2 g/mol.
- Divide the absolute value of the excess mass of hydrogen (|-1.16g|) by the molar mass of hydrogen (2 g/mol):
1.16g / 2 g/mol = 0.58 mol H2

7. Finally, we can determine the empirical formula by dividing the number of moles of each element by the smallest number of moles in the compound.
- Divide the number of moles of carbon (0.04 mol C) and hydrogen (0.58 mol H2) by 0.04 (the smallest number of moles):
0.04 mol C / 0.04 = 1 mol C
0.58 mol H2 / 0.04 = 14.5 mol H2

8. The resulting molar ratio is carbon:hydrogen = 1:14.5. We can simplify this ratio by multiplying each element's ratio by 2:
- Carbon: 1 * 2 = 2
- Hydrogen: 14.5 * 2 = 29

Therefore, the empirical formula of the hydrocarbon E is C2H29.