Question

State the number of moles in 39g of Al(OH)3.

A) 0.5 moles
B) 1 mole
C) 2 moles
D) 3 moles

Answer 1

To find the number of moles in 39g of Al(OH)3, we need to use the molar mass of Al(OH)3. The molar mass is calculated by adding up the atomic masses of each element in the compound. Then, we can use the formula Moles = Mass / Molar mass to calculate the number of moles. The correct answer is A) 0.5 moles.

Step-by-step explanation:

To find the number of moles in 39g of Al(OH)3, we need to use the molar mass of Al(OH)3. The molar mass is calculated by adding up the atomic masses of each element in the compound. The atomic masses of Al, O, and H are 26.98 g/mol, 16.00 g/mol, and 1.01 g/mol, respectively. Therefore, the molar mass of Al(OH)3 is (26.98 g/mol x 1) + (16.00 g/mol x 3) + (1.01 g/mol x 3) = 78.00 g/mol.

Next, we can use the formula Moles = Mass / Molar mass to calculate the number of moles. Substituting the values, we get Moles = 39g / 78.00 g/mol = 0.5 moles. Therefore, the correct answer is A) 0.5 moles.