Question

1. solid aluminum hydroxide is heated

Explanation:

To solve the problem of writing the chemical equation for heating solid aluminum hydroxide, we follow these steps:

Step 1: Identify the reactant and products

The reactant is solid aluminum hydroxide, with the chemical formula $\ce{Al(OH)_{3}(s)}$. When heated, metal hydroxides (especially those of transition metals and some post - transition metals like aluminum) decompose into the corresponding metal oxide and water vapor. So, the products will be aluminum oxide ($\ce{Al_{2}O_{3}(s)}$) and water vapor ($\ce{H_{2}O(g)}$).

Step 2: Balance the chemical equation

• First, let's consider the number of aluminum atoms. On the left side, we have 1 $\ce{Al}$ atom in $\ce{Al(OH)_{3}}$, and on the right side, we have 2 $\ce{Al}$ atoms in $\ce{Al_{2}O_{3}}$. So, we put a coefficient of 2 in front of $\ce{Al(OH)_{3}}$:
• Now the equation becomes $2\ce{Al(OH)_{3}(s)}\stackrel{\Delta}{=\!=\!=}\ce{Al_{2}O_{3}(s)}+\ce{H_{2}O(g)}$
• Next, let's balance the hydrogen and oxygen atoms. For hydrogen, in $2\ce{Al(OH)_{3}}$, we have $2\times3 = 6$ hydrogen atoms. On the right side, in $\ce{H_{2}O}$, we have 2 hydrogen atoms per molecule. So, to balance the hydrogen atoms, we need to put a coefficient of 3 in front of $\ce{H_{2}O}$ (since $3\times2=6$ hydrogen atoms).
• After balancing hydrogen, the oxygen atoms will also be balanced. The final balanced equation is:
• $2\ce{Al(OH)_{3}(s)}\stackrel{\Delta}{=\!=\!=}\ce{Al_{2}O_{3}(s)} + 3\ce{H_{2}O(g)}$

Answer:

The balanced chemical equation for heating solid aluminum hydroxide is $2\ce{Al(OH)_{3}(s)}\stackrel{\Delta}{=\!=\!=}\ce{Al_{2}O_{3}(s)}+3\ce{H_{2}O(g)}$