Question

1. in a combustion reaction, one of the products is always _______

a) hydrogen

b) carbon dioxide

c) oxygen

d) liquid

Explanation:

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<reasoning>

Identify the definition of a combustion reaction

\[
\text{Hydrocarbon} + \text{O}_2
ightarrow \text{CO}_2 + \text{H}_2\text{O}
\]

Analyze the given options

• A) Hydrogen: Usually a reactant or not present as elemental \(H_2\).
• B) Carbon dioxide: Always produced in the complete combustion of a hydrocarbon.
• C) Oxygen: A reactant, not a product.
• D) Liquid: Products can be in gaseous or other states depending on temperature.

Determine the correct choice

\[
\text{Correct Option} = \text{B}
\]
</reasoning>

<answer>
<mcq-option>(A) hydrogen</mcq-option>
<mcq-correct>(B) carbon dioxide</mcq-correct>
<mcq-option>(C) oxygen</mcq-option>
<mcq-option>(D) liquid</mcq-option>
</answer>

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Answer:

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<reasoning>

Identify the definition of a combustion reaction

\[
\text{Hydrocarbon} + \text{O}_2
ightarrow \text{CO}_2 + \text{H}_2\text{O}
\]

Analyze the given options

• A) Hydrogen: Usually a reactant or not present as elemental \(H_2\).
• B) Carbon dioxide: Always produced in the complete combustion of a hydrocarbon.
• C) Oxygen: A reactant, not a product.
• D) Liquid: Products can be in gaseous or other states depending on temperature.

Determine the correct choice

\[
\text{Correct Option} = \text{B}
\]
</reasoning>

<answer>
<mcq-option>(A) hydrogen</mcq-option>
<mcq-correct>(B) carbon dioxide</mcq-correct>
<mcq-option>(C) oxygen</mcq-option>
<mcq-option>(D) liquid</mcq-option>
</answer>

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