Crude oil may contain hundreds of different types of hydrocarbons. Some examples include:

- Butane [tex]$\left( C _4 H _{10}\right)$[/tex]
- Dodecane [tex]$\left( C _{12} H _{26}\right)$[/tex]
- Octane [tex]$\left( C _8 H _{18}\right)$[/tex]
- Benzene [tex]$\left( C _6 H _6\right)$[/tex]

Many common fuels, such as gasoline and kerosene, are combinations of these substances or others. When these fuels burn, they combine with oxygen [tex]$\left( O _2\right)$[/tex] to produce carbon dioxide [tex]$\left( CO _2\right)$[/tex] and water [tex]$\left( H _2 O \right)$[/tex].

Identify each of the highlighted materials as an element, a compound, or a mixture, and explain your reasoning.

[tex]$\square$[/tex]



Answer :

Let's analyze each of the highlighted materials and classify them as an element, a compound, or a mixture:

1. Butane [tex]$\left( \text{C}_4\text{H}_{10} \right)$[/tex]:
- Classification: Compound
- Reasoning: Butane is a substance composed of two different types of atoms, carbon (C) and hydrogen (H), chemically bonded together in a specific ratio (4 carbons to 10 hydrogens). Compounds are distinct substances that have a definite chemical composition.

2. Dodecane [tex]$\left( \text{C}_{12}\text{H}_{26} \right)$[/tex]:
- Classification: Compound
- Reasoning: Dodecane also consists of two different types of atoms, carbon (C) and hydrogen (H), chemically combined in a definite ratio (12 carbons to 26 hydrogens). This fixed composition classifies dodecane as a compound.

3. Octane [tex]$\left( \text{C}_8\text{H}_{18} \right)$[/tex]:
- Classification: Compound
- Reasoning: Octane is made up of carbon and hydrogen atoms chemically joined together in a proportion of 8 carbons to 18 hydrogens. Since it has a specific structural and chemical formula, octane is a compound.

4. Benzene [tex]$\left( \text{C}_6\text{H}_6 \right)$[/tex]:
- Classification: Compound
- Reasoning: Benzene consists of carbon (C) and hydrogen (H) atoms in a fixed ratio of 6 carbons to 6 hydrogens, forming a stable chemical structure. This uniform composition designates it as a compound.

5. Oxygen [tex]$\left( \text{O}_2 \right)$[/tex]:
- Classification: Element
- Reasoning: Oxygen in its diatomic form (O_2) consists of two oxygen atoms bonded together. Since it is made up of only one type of atom (oxygen), it is classified as an element.

6. Carbon Dioxide [tex]$\left( \text{CO}_2 \right)$[/tex]:
- Classification: Compound
- Reasoning: Carbon dioxide (CO_2) is composed of one carbon atom and two oxygen atoms chemically bonded together. As it contains more than one type of atom in a definite ratio, it is a compound.

7. Water [tex]$\left( \text{H}_2\text{O} \right)$[/tex]:
- Classification: Compound
- Reasoning: Water consists of hydrogen and oxygen atoms in a fixed ratio of 2 hydrogens to 1 oxygen. This uniform composition and chemical structure classify water as a compound.

Conclusion:

- Elements: Oxygen (O_2)
- Compounds: Butane (C_4H_{10}), Dodecane (C_{12}H_{26}), Octane (C_8H_{18}), Benzene (C_6H_6), Carbon Dioxide (CO_2), Water (H_2O)

Thus, each of these substances can be clearly categorized based on their chemical compositions and structures.