How many moles are there in 1.09 kg of Al(OH)3?

Answer: To calculate the number of moles in a given mass of a substance, you can use the formula:

Number of moles = Mass in grams / Molar mass

First, we need to determine the molar mass of Al(OH)_3. The molar mass is the sum of the atomic masses of all atoms in the molecule.

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

In one molecule of aluminum hydroxide, Al(OH)_3, we have:

1 Al atom = 1 x 26.98 g/mol = 26.98 g/mol 3 O atoms = 3 x 16.00 g/mol = 48.00 g/mol 3 H atoms = 3 x 1.01 g/mol = 3.03 g/mol

Now add these amounts together to find the molar mass of Al(OH)_3:

Molar mass of Al(OH)_3 = 26.98 g/mol + 48.00 g/mol + 3.03 g/mol = 78.01 g/mol

Next, convert the mass of Al(OH)_3 from kilograms to grams. Since there are 1000 grams in a kilogram, we get:

1.09 kg of Al(OH)_3 = 1.09 kg * 1000 g/kg = 1090 g

Now calculate the number of moles of Al(OH)_3:

Number of moles = Mass in grams / Molar mass Number of moles = 1090 g / 78.01 g/mol

Number of moles ≈ 13.97 moles of Al(OH)_3

So, there are approximately 13.97 moles in 1.09 kg of Al(OH)_3.