Question

Write the balanced chemical equation of the following word equation:

Aluminium + Sodium Hydroxide + Water → Sodium Meta Aluminate + Hydrogen

Answer 1

Balanced chemical equation:

• A chemical equation is a symbolic statement of any chemical reaction where the reactants and products are replaced by their chemical formulae and symbols.
• A balanced equation for a chemical reaction is where the number of atoms and charge of each chemical element is equal in both reactants and products of the reaction.

Chemical formulae:

• Aluminium: $\mathrm{Al}$
• Sodium Hydroxide: $\mathrm{NaOH}$
• Water: ${\mathrm{H}}_2\mathrm{O}$
• Sodium Meta Aluminate:${\mathrm{NaAlO}}_2$
• Hydrogen: ${\mathrm{H}}_2$

Equation:

$\mathrm{Al}\left(\mathrm{s}\right)+\mathrm{NaOH}\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to {\mathrm{NaAlO}}_2\left(\mathrm{aq}\right)+{\mathrm{H}}_2\left(\mathrm{g}\right)$

Balancing the equation:

• Checking the number of atoms on the reactants side and products side

	Reactants	Products
Al	1	1
Na	1	1
O	2	2
H	3	2

• Since the number of Hydrogen$\left(\mathrm{H}\right)$ atoms is not the same, the equation is not balanced.
• Equalizing the number of $\left(\mathrm{H}\right)$ atoms: $\mathrm{Al}\left(\mathrm{s}\right)+2\mathrm{NaOH}\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to {\mathrm{NaAlO}}_2\left(\mathrm{aq}\right)+2{\mathrm{H}}_2\left(\mathrm{g}\right)$

	Reactants	Products
Al	1	1
Na	2	1
O	3	2
H	4	4

• Balancing the number of $\mathrm{Na}$ atoms: $\mathrm{Al}\left(\mathrm{s}\right)+2\mathrm{NaOH}\left(\mathrm{aq}\right)+{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to 2{\mathrm{NaAlO}}_2\left(\mathrm{aq}\right)+2{\mathrm{H}}_2\left(\mathrm{g}\right)$

	Reactants	Products
Al	1	2
Na	2	2
O	3	4
H	4	4

• Balancing the number of $\mathrm{Al}$ and $\mathrm{O}$ atoms: $2\mathrm{Al}\left(\mathrm{s}\right)+2\mathrm{NaOH}\left(\mathrm{aq}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to 2{\mathrm{NaAlO}}_2\left(\mathrm{aq}\right)+2{\mathrm{H}}_2\left(\mathrm{g}\right)$

	Reactants	Products
Al	2	2
Na	2	2
O	4	4
H	6	4

• Balancing the number of $\mathrm{H}$ atoms: $2\mathrm{Al}\left(\mathrm{s}\right)+2\mathrm{NaOH}\left(\mathrm{aq}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to 2{\mathrm{NaAlO}}_2\left(\mathrm{aq}\right)+3{\mathrm{H}}_2\left(\mathrm{g}\right)$

	Reactants	Products
Al	2	2
Na	2	2
O	4	4
H	6	6

• The equation is balanced.

Final Balanced Equation

$2\mathrm{Al}\left(\mathrm{s}\right)+2\mathrm{NaOH}\left(\mathrm{aq}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)\to 2{\mathrm{NaAlO}}_2\left(\mathrm{aq}\right)+3{\mathrm{H}}_2\left(\mathrm{g}\right)$