Question

question 2 (2 points)
use the data from the previous question calculate the % oxygen in al₂(so₄)₃ to 5 significant figures.
these calculations are based upon mass. the % oxygen represents the mass of oxygen for every 100 g of aluminum sulfate.
1g o
% o =-----------------100 = 2 % oxygen
3g as
a. 1 b. 2 c. 3 d. 4 e. 5 f. 6 g. 7 h. 8
i. 9 j. 10 k. 12 l. 75.045 m. 150.09 n. 225.135
o. 342.15 p. 26.981 q. 32.065 r. 15.999 s. 53.962
t. 96.195 u. 191.988 v. 56.113

Explanation:

Step1: Calculate molar mass of \(Al_2(SO_4)_3\)

• Molar mass of \(Al\): \(2\times26.981 = 53.962\) g/mol
• Molar mass of \(S\): \(3\times32.065 = 96.195\) g/mol
• Molar mass of \(O\): \(12\times15.999 = 191.988\) g/mol
• Molar mass of \(Al_2(SO_4)_3\): \(53.962+96.195 + 191.988=342.145\approx342.15\) g/mol (matches option O)

Step2: Calculate mass of \(O\) in \(Al_2(SO_4)_3\)

• Mass of \(O\): \(12\times15.999 = 191.988\) g/mol (matches option U)

Step3: Calculate \(\%\) of \(O\)

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Answer:

U. 191.988, V. 56.113, O. 342.15