What is the percentage by
mass of oxygen in
Al2(SO4)3.2H2O?
A. 14.29%
B. 2539%
C. 50.79%
D. 59.25%
(Al = 27, S = 32, H=1, O=16)
First, let's calculate the molar mass of Al2(SO4)3.2H2O.
The molar mass of Al2(SO4)3 can be calculated as follows:
2(Al) + 3(S) + 12(O)
= 2(27) + 3(32) + 12(16)
= 54 + 96 + 192
= 342 g/mol
The molar mass of 2H2O can be calculated as follows:
2(2(H) + 16(O))
= 2(2 + 16)
= 2(18)
= 36 g/mol
So, the total molar mass of Al2(SO4)3.2H2O is:
342 + 36
= 378 g/mol
Now, let's calculate the molar mass of oxygen in Al2(SO4)3.2H2O.
The molar mass of oxygen in Al2(SO4)3.2H2O can be calculated as follows:
16(O) in Al2(SO4)3 + 16(O) in 2H2O
= 16 + 16
= 32 g/mol
Finally, let's calculate the percentage by mass of oxygen in Al2(SO4)3.2H2O.
Percentage by mass of oxygen = (molar mass of oxygen / total molar mass of Al2(SO4)3.2H2O) x 100%
= (32 g/mol / 378 g/mol) x 100%
≈ 8.47%
Therefore, the correct answer is not provided.
The Bot is wrong again.
The molar mass of Al2(SO4)3.2H2O is correctly listed as 378.
How many O atoms are in the molecule. There are 3*4 in the (SO4)3 + 2 in 2H2O = 14
The mass of the 14 O atoms = 14*16 = 224
mass % O in Al2(SO4)3.2H2O = (224/378)*100 = 59.25% which is answer D in the problem.
You are correct, and I apologize for the mistake in my previous response. The correct answer is indeed D. The percentage by mass of oxygen in Al2(SO4)3.2H2O is 59.25%. Thank you for pointing out the error.
To find the percentage by mass of oxygen in Al2(SO4)3.2H2O, we need to calculate the molar mass of Al2(SO4)3.2H2O first.
The molar mass of Al2(SO4)3 can be calculated as follows:
Al: 2 atoms x 27 g/mol = 54 g/mol
S: 3 atoms x 32 g/mol = 96 g/mol
O: 12 atoms x 16 g/mol = 192 g/mol
Adding up these masses, we get:
54 g/mol + 96 g/mol + 192 g/mol = 342 g/mol
The molar mass of H2O is:
2 atoms x 1 g/mol (H) + 16 g/mol (O) = 18 g/mol
Adding the molar masses of Al2(SO4)3 and H2O, we get:
342 g/mol + 18 g/mol = 360 g/mol
Now, let's calculate the mass of oxygen in Al2(SO4)3.2H2O:
The formula of Al2(SO4)3.2H2O tells us that there are 12 oxygen atoms.
So, 12 atoms x 16 g/mol = 192 g/mol (mass of oxygen in Al2(SO4)3.2H2O).
Finally, we can calculate the percentage by mass of oxygen:
(mass of oxygen / molar mass) x 100
(192 g/mol / 360 g/mol) x 100 = 53.33%
Therefore, the correct answer is not among the given choices. The correct percentage by mass of oxygen in Al2(SO4)3.2H2O is approximately 53.33%.