Here are the solutions to the chemistry questions:
b) Balance the following chemical equation
i) H$_{2(g)}$ + O$_{2(g)}$ $\rightarrow$ H$_{2}$O$_{(l)}$
Step 1: Balance oxygen atoms. There are 2 oxygen atoms on the left and 1 on the right. Place a coefficient of 2 in front of H$_{2}$O.
$$ \text{H}_{2(g)} + \text{O}_{2(g)} \rightarrow 2\text{H}_{2}\text{O}_{(l)} $$
Step 2: Balance hydrogen atoms. Now there are 2 hydrogen atoms on the left and $2 \times 2 = 4$ on the right. Place a coefficient of 2 in front of H$_{2}$.
$$ 2\text{H}_{2(g)} + \text{O}_{2(g)} \rightarrow 2\text{H}_{2}\text{O}_{(l)} $$
Step 3: Verify all atoms are balanced.
Reactants: H = 4, O = 2
Products: H = 4, O = 2
The equation is balanced.
$$ \boxed{2\text{H}_{2(g)} + \text{O}_{2(g)} \rightarrow 2\text{H}_{2}\text{O}_{(l)}} $$
ii) KClO$_{3(s)}$ $\rightarrow$ KCl$_{(s)}$ + O$_{2(g)}$
Step 1: Balance oxygen atoms. There are 3 oxygen atoms on the left and 2 on the right. The least common multiple of 3 and 2 is 6. Place a coefficient of 2 in front of KClO$_{3}$ and 3 in front of O$_{2}$.
$$ 2\text{KClO}_{3(s)} \rightarrow \text{KCl}_{(s)} + 3\text{O}_{2(g)} $$
Step 2: Balance potassium and chlorine atoms. Now there are 2 potassium and 2 chlorine atoms on the left, but only 1 of each on the right. Place a coefficient of 2 in front of KCl.
$$ 2\text{KClO}_{3(s)} \rightarrow 2\text{KCl}_{(s)} + 3\text{O}_{2(g)} $$
Step 3: Verify all atoms are balanced.
Reactants: K = 2, Cl = 2, O = 6
Products: K = 2, Cl = 2, O = 6
The equation is balanced.
$$ \boxed{2\text{KClO}_{3(s)} \rightarrow 2\text{KCl}_{(s)} + 3\text{O}_{2(g)}} $$
iii) K$_{2}$CO$_{3(s)}$ + HCl$_{(aq)}$ $\rightarrow$ KCl$_{(aq)}$ + CO$_{2(g)}$ + H$_{2}$O$_{(l)}$
Step 1: Balance potassium atoms. There are 2 potassium atoms on the left and 1 on the right. Place a coefficient of 2 in front of KCl.
$$ \text{K}_{2}\text{CO}_{3(s)} + \text{HCl}_{(aq)} \rightarrow 2\text{KCl}_{(aq)} + \text{CO}_{2(g)} + \text{H}_{2}\text{O}_{(l)} $$
Step 2: Balance chlorine atoms. Now there is 1 chlorine atom on the left and 2 on the right. Place a coefficient of 2 in front of HCl.
$$ \text{K}_{2}\text{CO}_{3(s)} + 2\text{HCl}_{(aq)} \rightarrow 2\text{KCl}_{(aq)} + \text{CO}_{2(g)} + \text{H}_{2}\text{O}_{(l)} $$
Step 3: Verify all atoms are balanced.
Reactants: K = 2, C = 1, O = 3, H = 2, Cl = 2
Products: K = 2, C = 1, O = 2 (from CO$_{2}$) + 1 (from H$_{2}$O) = 3, H = 2, Cl = 2
All atoms are balanced.
$$ \boxed{\text{K}_{2}\text{CO}_{3(s)} + 2\text{HCl}_{(aq)} \rightarrow 2\text{KCl}_{(aq)} + \text{CO}_{2(g)} + \text{H}_{2}\text{O}_{(l)}} $$
10 (a) Construct the Diagram to show the electronic structure in each of the following compounds
I. Oxygen gas (O$_{2}$)
Step 1: Determine the total number of valence electrons. Each oxygen atom has 6 valence electrons. For O$_{2}$, there are $2 \times 6 = 12$ valence electrons.
Step 2: Draw a single bond between the two oxygen atoms. This uses 2 electrons.
$$ \text{O}-\text{O} $$
Step 3: Distribute the remaining $12 - 2 = 10$ electrons as lone pairs to complete octets. If a single bond is used, each oxygen would need 6 more electrons (3 lone pairs) to complete its octet, totaling 12 lone pair electrons. Since only 10 are available, a single bond is not sufficient.
Step 4: Form a double bond between the oxygen atoms. This uses 4 electrons.
$$ \text{O}=\text{O} $$
Step 5: Distribute the remaining $12 - 4 = 8$ electrons as lone pairs. Each oxygen atom needs 4 more electrons (2 lone pairs) to complete its octet ($4 \text{ (from bond)} + 4 \text{ (lone pairs)} = 8$).
$$ \text{:\overset{\bullet\bullet}{O}}=\overset{\bullet\bullet}{\text{O}:} $$
Step 6: Verify octets for both atoms. Each oxygen atom has 4 bonding electrons (from the double bond) and 4 non-bonding electrons (from two lone pairs), totaling 8 electrons. Both octets are satisfied.
The electronic structure (Lewis structure) for oxygen gas (O$_{2}$) is:
$$ \boxed{\text{:\overset{\bullet\bullet}{O}}=\overset{\bullet\bullet}{\text{O}:}} $$