Question

Rewrite the following information in the form of a balanced chemical equation.

“Magnesium burns in carbon dioxide to form magnesium oxide and carbon.”

Answer 1

1. Balanced chemical equation- In a balanced chemical equation, the number of atoms of each element should be equal on both sides of the reaction.
2. Given information: Magnesium burns in carbon dioxide to form magnesium oxide and carbon.
3. Chemical formula for each substance:

Chemical name	Chemical formula
Magnesium	$\mathrm{Mg}$
Carbon dioxide	${\mathrm{CO}}_2$
Magnesium oxide	$\mathrm{MgO}$
Carbon	$\mathrm{C}$

4. Chemical equation- Thus, the given information is written in form of a chemical equation as-

$\mathrm{Mg}\left(\mathrm{s}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)\to \mathrm{MgO}\left(\mathrm{s}\right)+\mathrm{C}\left(\mathrm{s}\right)$

Thus, the number of atoms of each element as per this equation is-

Element	Number of atoms on reactant side	Number of atoms on product side
Magnesium ($\mathrm{Mg}$)	1	1
Carbon ($\mathrm{C}$)	1	1
Oxygen ($\mathrm{O}$)	2	1

5. Balancing of $\mathrm{O}$ : To balance $\mathrm{O}$ atoms, coefficient 2 is added in front of $\mathrm{MgO}$.

$\mathrm{Mg}\left(\mathrm{s}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)\to 2\mathrm{MgO}\left(\mathrm{s}\right)+\mathrm{C}\left(\mathrm{s}\right)$

Number of atoms after adding coefficient-

Element	Number of atoms on reactant side	Number of atoms on product side
Magnesium ($\mathrm{Mg}$)	1	2
Carbon ($\mathrm{C}$)	1	1
Oxygen ($\mathrm{O}$)	2	2

6. After balancing $\mathrm{O}$ atom, $\mathrm{Mg}$ atoms become unbalanced which are made equal on both sides by adding coefficient 2 in front of $\mathrm{Mg}$.

$2\mathrm{Mg}\left(\mathrm{s}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)\to 2\mathrm{MgO}\left(\mathrm{s}\right)+\mathrm{C}\left(\mathrm{s}\right)$

Element	Number of atoms on reactant side	Number of atoms on product side
Magnesium ($\mathrm{Mg}$)	2	2
Carbon ($\mathrm{C}$)	1	1
Oxygen ($\mathrm{O}$)	2	2

Hence, the equation becomes balanced.

5. Balanced equation: Hence, the balanced equation is-

$$\begin{gathered} 2\mathrm{Mg}\left(\mathrm{s}\right)+{\mathrm{CO}}_2\left(\mathrm{g}\right)\to 2\mathrm{MgO}\left(\mathrm{s}\right)+\mathrm{C}\left(\mathrm{s}\right) \\ \mathrm{Magnesium}\mathrm{Carbon}\mathrm{Magnesium}\mathrm{Carbon} \\ \mathrm{dioxide}\mathrm{oxide} \end{gathered}$$