7.50 g of a compound that contains hydrogen, carbon and oxygen, which produces 11.0 g of carbon dioxide and 4.5 g of water when burned, contains 0.25 moles of carbon in the original sample.
<h2 /><h2>Further Explanation:
</h2><h3>A compound
</h3>
- A compound is a substances that contains two or more different atoms that are bonded together.
- When the atoms are similar the substance is known as a molecule, therefore not all molecules are compounds.
<h3>Hydrocarbons </h3>
- Hydrocarbons are compounds that contains hydrogen and carbon as the only elements. Other hydrocarbons are composed of hydrogen, carbon and oxygen elements.
- When hydrocarbons are burned in air, they form carbon dioxide and water:
That is;
CxHyOn + O2 = CO2 + H2O
Moles of carbon in the original sample of a Hydrocarbon
- We can calculate the original number of moles in the original sample of the hydrocarbon.
In our case:
Mass of CO2 formed is 11.0 g
Mass of the hydrocarbon is 7.5 g
Mass of carbon:
1 mole of CO2 contains 12.0 g of carbon
44.0 g/mol contains 12.0 g of carbon
Hence; 11.0 g of CO2 will contain;
= (11x 12)/44.0g
= 3 g of carbon
This means; the original mass of Carbon in 7.5 g of the hydrocarbon is 3 g
Number of moles = mass/R.A.M
= 3 g/ 12.0 g/mol
= 0.25 moles
Hence; 7.5 g of the hydrocarbon contained 0.25 moles of carbon.
<h3>Learn more about:
</h3>
Level: High school
Subject: Chemistry
Topic: Empirical formula and molecular formula
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