Lesson: Chapter 7 — Quantification of Elements and Compounds

7.2. Relative molecular mass 5 of 10 Reset answers

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Question 5

What is the relative molecular mass of glucose (C₆H₁₂O₆)? (A_r: H = 1, C = 12, O = 16)

A 90 B 168 C 180 D 29

The right answer is the one marked above.

180. (6 × 12) + (12 × 1) + (6 × 16) = 72 + 12 + 96 = 180.

29 comes from taking 12 + 1 + 16 and ignoring every subscript. 168 comes from forgetting to add the 12 hydrogens.

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