Calculate the percentage by mass of O in Ca(OH). (H = 1, C = 12, N = 14, O = 16, Mg = 24, S = 32, Cl = 35.5, Al = 27, Ca = 40, Fe = 56, Cu = 63.5, Na = 23)
Answer and explanation
Correct answer: A. 43.2%
- Step 1: of Ca(OH) .
- Step 2: Mass of O in one formula unit .
- Step 3: Percentage .
Answer
43.2%.
Why not the others: 21.6%: the number of atoms in the formula is ignored. 56.8%: that is the percentage of all the other elements.
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