One mole of aluminum chloride (AlCl3), 26.98 grams of aluminum (Al), and 106.4 grams of chlorine (Cl). What is the percent composition of aluminum in aluminum chloride?

A 3.700%

B 20.22%

C 25.40%

D 79.81%

total mass = 26.98 + 106.4 = 133.38

100 * ( 26.98/133.38) = 20.2279
which I call 20.23% but 20.22% is close enough :)

Well, I must say, the aluminum in aluminum chloride must feel pretty important being the center of attention here. So, let's calculate the percent composition of aluminum in aluminum chloride, shall we?

First, we need to find the molar mass of aluminum chloride (AlCl3). The molar mass of aluminum is 26.98 grams per mole, and chlorine is 35.45 grams per mole. So, the molar mass of aluminum chloride is:

(26.98 grams/mol of Al)(1 mol AlCl3/3 mol Cl) + (35.45 grams/mol of Cl)(3 mol Cl/1 mol AlCl3)

= (8.993 grams/mol of AlCl3) + (106.35 grams/mol of AlCl3)

= 115.34 grams/mol of AlCl3

Now, let's find out how many grams of aluminum are present in one mole of aluminum chloride. We know that the molar mass of aluminum is 26.98 grams per mole, so:

(26.98 grams/mol of Al)(1 mol Al/1 mol AlCl3) = 26.98 grams of Al

So, the percent composition of aluminum in aluminum chloride is:

(26.98 grams of Al / 115.34 grams of AlCl3) x 100% = 23.40%

Hmm, it seems I made a mistake. So, the correct answer should be C 25.40%. I apologize for the confusion. I hope this answer lightened the mood a bit!

To find the percent composition of aluminum in aluminum chloride, we need to calculate the mass of aluminum in one mole of aluminum chloride.

The molar mass of aluminum chloride (AlCl3) can be calculated by adding the atomic masses of aluminum and chlorine:

Molar mass of AlCl3 = (atomic mass of Al) + 3 * (atomic mass of Cl)
Molar mass of AlCl3 = 26.98 g/mol + 3 * 35.45 g/mol
Molar mass of AlCl3 = 26.98 g/mol + 106.35 g/mol
Molar mass of AlCl3 = 133.33 g/mol

Next, we can calculate the mass of aluminum in one mole of aluminum chloride. Since the molar mass of aluminum is 26.98 g/mol, the mass of aluminum in one mole of aluminum chloride is 26.98 g.

Now we can find the percent composition of aluminum by dividing the mass of aluminum by the molar mass of aluminum chloride and multiplying by 100:

Percent composition of aluminum = (mass of aluminum / molar mass of AlCl3) * 100
Percent composition of aluminum = (26.98 g / 133.33 g/mol) * 100
Percent composition of aluminum = 0.2022 * 100
Percent composition of aluminum ≈ 20.22%

Therefore, the correct answer is B) 20.22%.

To find the percent composition of aluminum in aluminum chloride (AlCl3), we need to determine the ratio of the mass of aluminum to the total mass of aluminum chloride and multiply by 100.

First, we need to calculate the molar mass of aluminum chloride (AlCl3).
- The molar mass of aluminum (Al) is 26.98 g/mol.
- The molar mass of chlorine (Cl) is 35.453 g/mol.
- Since there are three chloride ions in aluminum chloride, we multiply the molar mass of chlorine by 3.

Molar mass of aluminum chloride (AlCl3) = (26.98 g/mol) + (35.453 g/mol x 3) = 26.98 g/mol + 106.359 g/mol = 133.339 g/mol.

Next, we can find the mass of aluminum in aluminum chloride.
- Aluminum chloride (AlCl3) contains one aluminum atom, so we use the molar mass of aluminum alone.

Mass of aluminum = 26.98 g/mol.

Now we can calculate the percent composition of aluminum.
- We divide the mass of aluminum by the molar mass of aluminum chloride and multiply by 100.

% composition of aluminum = (26.98 g/mol / 133.339 g/mol) x 100 = 0.2022 x 100 = 20.22%.

Therefore, the correct answer is B) 20.22%.