Question

Aluminum chlorohydrate, al2(oh)5cl, is an active ingredient in some antiperspirants. what is the mass percent of aluminum in this compound?

Answer 1

The mass percent of aluminum in aluminum chlorohydrate, Al2(OH)5Cl, is calculated by dividing the mass of aluminum in the compound by the compound's total molar mass and then multiplying by 100, which results in approximately 30.94%.

Step-by-step explanation:

To calculate the mass percent of aluminum in aluminum chlorohydrate, Al2(OH)5Cl, we first need to find the molar mass of aluminum and the molar mass of the entire compound. The molar mass of aluminum is approximately 26.98 g/mol and there are two aluminum atoms in the compound. Next, calculate the total molar mass of Al2(OH)5Cl using the molar masses of all the atoms involved.

For Al2(OH)5Cl:

• Molar mass of Al: 26.98 g/mol × 2 = 53.96 g/mol
• Molar mass of O: 16.00 g/mol × 5 = 80.00 g/mol
• Molar mass of H: 1.01 g/mol × 5 = 5.05 g/mol
• Molar mass of Cl: 35.45 g/mol

Total molar mass of Al2(OH)5Cl = 53.96 + 80.00 + 5.05 + 35.45 = 174.46 g/mol

Mass percent of Aluminium in the compound = (Mass of Al in the formula / Molar mass of the compound) × 100 = (53.96 / 174.46) × 100 = 30.94%

Answer 2

The percet of Al will be 100 times the mass of Al in the formula divided by the molar mass of the compound.

This table shows all the calculations involved

Compound: Al2 (OH)5 Cl

element # of atomic mass in the %
atoms mass formula
g/mol

Al 2 27 2*27 = 54 g (54 / 174.5)*100 = 30.9%

O 5 16 5*16 = 80 g

H 5 1 5*1 = 5 g

Cl 1 35.5 1*35.5 = 35.5 g
----------------------
molar mass 174.5 g

Answer: 30.9%