Question

81.4 g sample of ethyl alcohol contains 0.002 g of water. The amount of pure ethyl alcohol to the proper number of significant figures is

• A. 81.398 g
• B. 71.40 g
• C. 91.4 g
• D. 81 g

Answer 1

Answer: (A)

81.398 g

Answer 2

Pure ethyl alcohol $= 81.4 - 0.002 = 81.398$.