Question

A sample of glucose, C6H12O6, contains 1.280×1021 carbon atoms.

Part 1: How many atoms of hydrogen does it contain?

Part 2: How many molecules of glucose does it contain?

Part3: How many moles of glucose does it contain?

Part 4: What is the mass of this sample in grams?

Answer 1

1. ratio of Hydrogen to Carbon atoms in glucose = 12 / 6 = 2

Atoms of H = 2 * atoms of C = 2 * 1.28 * 10²¹ = 2.56 * 10²¹ atoms

2. Atoms of glucose = atoms of C / 6 = 1.28 * 10²¹ / 6 = 2.13 * 10²⁰ molecules

3. Moles of glucose = molecules of glucose / Avogadro Number = 2.13 * 10²⁰ / 6.022 * 10²³ = 3.54 * 10^-4 moles

4. Mass = moles * molar mass = 3.54 * 10^-4 * 180 = 0.064 g