Answer :
A sample of trifluoroacetic acid, C₂HF₃O₂, contains 39. 3 g of oxygen. The mass of the trifluoroacetic acid sample is 140 g.
The molecular mass of trifluoroacetic acid is as :
C₂HF₃O₂ = ( 2× 12) + 1 + (3 × 19 ) + (2 ×16)
= 114 g/mol
In one molecule of C₂HF₃O₂ , there are the two molecules of oxygen. The 114 amu of the trifluoroacetic acid contains = 2 × 16 = 32 g/mol
Therefore, the mass of trifluoroacetic acid = (114/32) × 39.3
The mass of trifluoroacetic acid = 140 g
Thus, the mass of the trifluoroacetic acid, C₂HF₃O₂ is 140 g.
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