Let's break down the chemical formula for aluminum hydroxide, [tex]\( \text{Al(OH)}_3 \)[/tex], step by step to understand its composition and determine which of the statements are true.
1. Identify the number of aluminum (Al) atoms:
- The formula [tex]\( \text{Al(OH)}_3 \)[/tex] shows an "Al" without any number following it, which implies there is 1 aluminum atom present.
2. Identify the number of OH groups:
- The subscript "3" after the (OH) indicates there are 3 hydroxide (OH) groups attached to one aluminum atom.
3. Determine the composition of OH groups:
- Each OH group consists of 1 oxygen (O) atom and 1 hydrogen (H) atom.
4. Calculate the total number of oxygen atoms:
- Since there are 3 OH groups and each OH group contains 1 oxygen atom:
[tex]\[
\text{Total Oxygen Atoms} = 3 \times 1 = 3 \text{ oxygen atoms}
\][/tex]
Now, let's evaluate the statements one by one:
1. It contains three molecules:
- This statement is incorrect. The chemical formula given, [tex]\( \text{Al(OH)}_3 \)[/tex], represents a single molecule of aluminum hydroxide, not three molecules.
2. It has three aluminum (Al) atoms:
- This statement is incorrect. The formula indicates there is only 1 aluminum atom in a molecule of aluminum hydroxide.
3. It has three OH groups:
- This statement is correct. The subscript "3" after the (OH) clearly indicates that there are 3 hydroxide groups present.
4. It contains exactly one oxygen atom:
- This statement is incorrect. From our calculation, we determined there are 3 oxygen atoms present in a single molecule of aluminum hydroxide.
Therefore, the true statement about aluminum hydroxide is:
- It has three OH groups.
