How many moles are in 98.3 g of [tex]Al(OH)_3[/tex]?

To find out how many moles are in 98.3 grams of aluminum hydroxide, [tex]$ \text{Al(OH)}_3 $[/tex], we need to follow these steps:

1. Determine the molar mass of [tex]$ \text{Al(OH)}_3 $[/tex]:

- Aluminum (Al) has an atomic mass of approximately 26.98 g/mol.
- Oxygen (O) has an atomic mass of approximately 16.00 g/mol.
- Hydrogen (H) has an atomic mass of approximately 1.01 g/mol.

2. Calculate the molar mass of [tex]$ \text{Al(OH)}_3 $[/tex]:

- There is one aluminum atom in [tex]$ \text{Al(OH)}_3 $[/tex]: [tex]$ 1 \times 26.98 = 26.98 \, \text{g/mol} $[/tex]
- There are three oxygen atoms: [tex]$ 3 \times 16.00 = 48.00 \, \text{g/mol} $[/tex]
- There are three hydrogen atoms: [tex]$ 3 \times 1.01 = 3.03 \, \text{g/mol} $[/tex]

Add these together to get the molar mass of [tex]$ \text{Al(OH)}_3 $[/tex]:

[tex]\[
26.98 + 48.00 + 3.03 = 78.01 \, \text{g/mol}
\][/tex]

3. Calculate the number of moles of [tex]$ \text{Al(OH)}_3 $[/tex]:

To find the number of moles, use the formula:

[tex]\[
\text{Number of moles} = \frac{\text{Given mass}}{\text{Molar mass}}
\][/tex]

Given the mass of [tex]$ \text{Al(OH)}_3 $[/tex] is 98.3 grams, we can calculate the number of moles:

[tex]\[
\text{Number of moles} = \frac{98.3 \, \text{g}}{78.01 \, \text{g/mol}}
\][/tex]

[tex]\[
\text{Number of moles} \approx 1.26
\][/tex]

Therefore, there are approximately 1.26 moles in 98.3 grams of [tex]$ \text{Al(OH)}_3 $[/tex].