Question

Solid carbon (C) can burn in oxygen (O2). Select

Answer 1

Answer:

• CO₂

Explanation:

The equation that you have to complete is:

• C + O₂ → ?

This is, you have to find the products formed and the coefficients in front of each substance to balance the chemical equation.

Carbon may react with oxygen using oxidation number 2 or 4.

If carbon uses oxidation number 2, the chemical equation is:

• 2C + O₂ → 2CO

If carbon uses oxidation number 4, the chemical equation is:

• C + O₂ → CO₂

Normally, an incomplete combustion yields to a mixture of products: both CO and CO₂, and it only happens when the amount of oxygen is limitied.

When there is plenty of oxygen available, the combustion is complete and the only product of the reaction is CO₂.

With that information, and the fact that the list of choices do not include CO as product, you conclude that this is a complete combustion, and the chemical equation is:

• C + O₂ → CO₂

So, the choice that completes the chemical equation is CO₂.