College Chemistry 1

Question

Leucine is an amino acid with the formula . C6H13NO2 Determine the number of moles of carbon in 94.34g  of leucine.

Answer 1

Find moles of leucine and then moles of C

moles leucine = 94.34 g leucine x 1 mole/131 g = 0.720 moles leucine

Each mole of leucine contains 6 moles of C (carbon)

Moles of carbon = 0.720 mol Leucine x 6 mol C/mol leucine = 4.321 moles C

Answer 2

1 mole C₆H₁₃NO₂ = 6 x 12.0 + 13 x 1.0 + 2 x 16.0 = 117.0 g (it is the molar mass of leucine)

93.34 g x 1 mole / 117.0 g = 0.7978 mole