Question

0.2g of organic compound containing carbon, hydrogen and oxygen on combustion yielded 0.147gCO₂ and 0.12g water. What will be the content of oxygen in the substance?

A. 78.45%
B. 73.295%
C. 83.23%
D. 89.50%

Answer 1

The content of oxygen in the substance is 7.09%.

Step-by-step explanation:

To determine the content of oxygen in the substance, we need to calculate the amount of carbon and hydrogen present in the organic compound. From the combustion reaction, we know that 0.2g of the compound produced 0.147g CO₂ and 0.12g water. Using the molar masses of carbon, hydrogen, and oxygen, we can calculate the moles of carbon and hydrogen in the compound. Then, we can use the balanced equation for the combustion reaction to find the moles of oxygen. Finally, we can convert the moles of oxygen to grams and calculate the percentage of oxygen in the substance:

1. Moles of carbon: 0.147g CO₂ * (1 mole CO₂ / 44.01g CO₂) * (1 mole C / 1 mole CO₂) = 0.00334 moles C
2. Moles of hydrogen: 0.12g H₂O * (1 mole H₂O / 18.02g H₂O) * (2 moles H / 1 mole H₂O) = 0.0133 moles H
3. Moles of oxygen: 0.2g - (0.00334 moles C * 12.01g C + 0.0133 moles H * 1.01g H) = 0.00113 moles O
4. Percentage of oxygen: (0.00113 moles O * 16.00g O / 1 mole O) / 0.2g * 100% = 7.09%