Question

Which of the following compounds has the highest oxygen content by weight?

Answer 1

The molecular weight is 18, and 16 of that is oxygen.  

So, water is 16/18 * 100 = 88.9% oxygen by weight.  

None of the other compounds have as high an oxygen content (by weight) as water.  

This is a trick question, and the University Chemistry grad fell for it.  

If you have the same weight of each compound (let's say, 10 grams, for example), then H2O has the most oxygen weight (8.89 g).

Answer 2

Answer:

This question is incomplete. The completed question is below

Which of the following compounds has the highest oxygen content, by weight? a. NaO b. CO c. BaO  d. H₂O

The correct option is d. H₂O

Explanation:

The percentage of oxygen by weight in NaO is

atomic mass of sodium (Na) is 23 g/mol while that of oxygen is 16 g/mol

molar mass of NaO = 23 + 16 = 39g

% by mass of oxygen  = 16/39 × 100 = 41.03 %

The percentage of oxygen by weight in CO is

atomic mass of carbon (C) is 12 g/mol while that of oxygen is 16 g/mol

molar mass of CO = 12 + 16 = 28g

% by mass of oxygen = 16/28 × 100 = 57.14 %

The percentage of oxygen by weight in BaO is

atomic mass of barium (Ba) is 137 g/mol while that of oxygen is 16 g/mol

molar mass of BaO = 137 + 16 = 153g

% by mass of oxygen = 16/153 × 100 = 10.46 %

The percentage of oxygen by weight in H₂O is

atomic mass of Hydrogen (H) is 1 g/mol while that of oxygen is 16 g/mol

 molar mass of H₂O = (2 × 1) + 16 = 18g

% by mass of oxygen = 16/18 × 100 = 88.89 %

From the above calculations, it can be deduced that H₂O has the highest oxygen content by weight