Question

Give the balanced equation for each of the following chemical reactions

a.Glucose$\left({\mathbf{C}}_{\mathbf{6}}{\mathbf{H}}_{\mathbf{12}}{\mathbf{O}}_{\mathbf{6}}\right)$reacts with oxygen gas to produce gaseous carbon dioxide and water vapour.

b. Solid iron$\left(\mathbf{III}\right)$ sulfide reacts with gaseous hydrogen chloride to form solid iron$\left(\mathbf{III}\right)$ chloride and hydrogen sulfide gas.

c. Carbon disulfide liquid reacts with ammonia gas to produce hydrogen sulphide gas and solid ammonium thiocyanate$\left({\mathbf{NH}}_{\mathbf{4}}\mathbf{SCN}\right)$ .

Short answer

The balanced equation for each of the following chemical reactions are:

(a)$\left(C_6{H}_{12}{O}_6\right)\left(s\right)+6O_2\left(g\right)\to 6C{O}_2\left(g\right)+6H_{2}O\left(g\right)$

(b) ${\text{Fe}}_2{\text{S}}_3\left(g\right)+6HCl\left(g\right)\to 2FeC{l}_3\left(g\right)+3H_{2}S\left(g\right)$

(c) $C{S}_2\left(l\right)+2N{H}_3\left(g\right)\to H_{2}S\left(g\right)+N{H}_{4}SCN\left(s\right)$

Step-by-step solution

Definition

Atoms are preserved in chemical reactions; therefore, balancing is crucial. The number of atoms in each type of reactant and product must be equal. In addition, an unbalanced chemical equation has limited utility.It's important to remember that the formulae of the compounds remain the same while balancing a chemical equation.

The unbalanced chemical equation

a)

The reactants are glucose$\left(C_6{H}_{12}{O}_6\right)$and oxygen $\left(O_2\right)$, and the products are carbon dioxide$\left(C{O}_2\right)$and water vapor $\left(H_{2}O\right)$in the given chemical reaction.

$\left(C_6{H}_{12}{O}_6\right)\left(s\right)+O_2\left(g\right)\to C{O}_2\left(g\right)+H_{2}O\left(g\right)$

is an imbalanced chemical equation.

The chemical equation to be balanced

For a chemical equation to be balanced, the number of atoms of each kind must be the same in both the reactant and the product.

There are 12 hydrogens on the left side and 2 on the right side of the balancing hydrogen. There will be 12 hydrogen atoms on both sides when coefficient 6 is applied to$\left(H_{2}O\right)$.

Similarly, if $\left(C{O}_2\right)$is given the coefficient 6, there will be 6 carbon atoms on both sides.

$\left(C_6{H}_{12}{O}_6\right)\left(s\right)+O_2\left(g\right)\to 6C{O}_2\left(g\right)+6H_{2}O\left(g\right)$

The reaction of GlucoseC6H12O6 reacts with oxygen gas

When it comes to balancing oxygen, there are 8 atoms on the left (6 from $\left(C_6{H}_{12}{O}_6\right)$and 2 from $\left(O_2\right)$) and 18 on the right (12 from $\left(C{O}_2\right)$, and 6 from $\left(H_{2}O\right)$). There will be 18 oxygen atoms on both sides if coefficient 6 is set to $\left(O_2\right)$on both sides.

As a result, the balanced chemical equationrequired will be:

$\left(C_6{H}_{12}{O}_6\right)\left(s\right)+6O_2\left(g\right)\to 6C{O}_2\left(g\right)+6H_{2}O\left(g\right)$

The unbalanced chemical equation

b)

Solid iron $\left(\text{III}\right)$sulfide,${\text{Fe}}_2{\text{S}}_3\left(\text{s}\right)$ and gaseous hydrogen chloride,$\text{HCI}\left(\text{g}\right)$are reactants and solid iron$\left(\text{III}\right)$chloride ${\text{FeCl}}_3\left(\text{s}\right)$ and hydrogen sulfide gas $H_{2}S\left(g\right)$are products.

Because $F{e}^{3+}$ions are present in iron $\left(\text{III}\right)$sulfide and the sulfide ion is $S^{2-}$, the formula for iron $\left(\text{III}\right)$ sulfide is ${\text{Fe}}_2{\text{S}}_3$. Because the ion of chloride is $C{l}^{-}$, the formula for iron $\left(\text{III}\right)$chloride is ${\text{FeCl}}_3$.

${\text{Fe}}_2{\text{S}}_3\left(\text{s}\right)+HCl\left(g\right)\to FeC{l}_3\left(s\right)+H_{2}S\left(g\right)$ is the imbalanced chemical equation.

The chemical equation to be balanced

Starting with iron, there are two atoms on the left side and one on the right side.

If ${\text{FeCl}}_3\left(\text{s}\right)$has a coefficient of 2, there will be two iron atoms on both sides.

${\text{Fe}}_2{\text{S}}_3\left(\text{s}\right)+HCl\left(g\right)\to 2FeC{l}_3\left(s\right)+H_{2}S\left(g\right)$

Step 7: Solid IronIII sulfide reacts with gaseous hydrogen chloride

There are 6 chlorine atoms on the right side and 1 atom on the left side of the balance. There will be 6 atoms of chlorine on both sides when coefficient 6 is applied to$\text{HCI}$. In the same way, balancing hydrogen by assigning coefficient 3 to $H_{2}S$ will result in 6 hydrogen atoms on both sides.

As a result, the balanced chemical equation required will be:

${\text{Fe}}_2{\text{S}}_3\left(g\right)+6HCl\left(g\right)\to 2FeC{l}_3\left(g\right)+3H_{2}S\left(g\right)$

The imbalanced chemical equation

c)

The reactants are liquid carbon disulfide$C{S}_2\left(l\right)$ and ammonia gas${\text{NH}}_3\left(\text{g}\right)$, whereas the products are hydrogen sulfide gas$\left({\text{H}}_2\text{S}\right)\left(g\right)$ and solid ammonium thiocyanate$\left({\text{NH}}_4\text{SCN}\right)\left(s\right)$.

$C{S}_2\left(l\right)+N{H}_3\left(g\right)\to H_{2}S\left(g\right)+N{H}_{4}SCN\left(s\right)$is an imbalanced chemical equation.

Step 9: Carbon disulfide liquid reacts with ammonia gas

The number of carbon and sulfur atoms is already balanced in the above equation. To be balanced, only nitrogen and hydrogen atoms are required.

On both sides of the equation, if coefficient 2 is applied to${\text{NH}}_3$, there will be 2 nitrogen atoms and 6 hydrogen atoms.

As a result, the balanced chemical equation required is:

$C{S}_2\left(l\right)+2N{H}_3\left(g\right)\to H_{2}S\left(g\right)+N{H}_{4}SCN\left(s\right)$