Question

How many moles of glucose, C6H12O6, are in a sample which weighs 75.5 g? (Hint: your answer needs to be less than the 1 mole b/c you're asked about the mole equivalent of 75.5g, which is less than 1 mole of glucose)

Answer 1

There are 0,419 moles of glucose in a sample that weights 75.5g.

To calculate the amount in moles of glucose in 75.5g, we first need the molar mass of this compound. To calculate that I'll be using the following atomic mass values:

C: 12

H: 1

O: 16

To calculate the molar mass, we multiply the number of atoms by the respective atomic mass:

(6 * 12) + (12 * 1) + (6 * 16) = 180 g/mol

Since the molar mass is 180 g/mol, we know that each mol has 180 g of glucose:

1 mol glucose ---------- 180g glucose

x --------------------------- 75.5g glucose

Solving for x, we have x = 0.419 moles of glucose