If 3.50 g of the unknown compound contained 0.117 mol of C and 0.233 mol of H, how many moles of oxygen, O, were in the sample? Express your answer to three significant figures and include the appropriate units.

Question

Chemistry

Isaac Kirk

13 December, 00:06

If 3.50 g of the unknown compound contained 0.117 mol of C and 0.233 mol of H, how many moles of oxygen, O, were in the sample? Express your answer to three significant figures and include the appropriate units.

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Answers (1)

Know the Answer?

Rory Davila · Answer 1

0.116 g.

Explanation:

Firstly, we can find the mass of C and H in the unknown compound:

mass of C = (no. of moles of C) (atomic mass of C) = (0.117 mol) (12.01 g/mol) = 1.405 g.

mass of H = (no. of moles of H) (atomic mass of H) = (0.233 mol) (1.01 g/mol) = 0.235 g.

∴ mass of O = mass of unknown sample - (mass of C + mass of H) = 3.50 g - (1.405 g + 0.235) = 1.86 g.

∴ no. of moles of O = (mass of O) / (atomic mass of O) = (1.86 g) / (16.0 g/mol) = 0.116 g.