Question

A doctor recommended 20 mg of glucose (C6H12O6

) for a child per day. Find the number of
molecules of glucose in that amount

Answer 1

To find the number of glucose molecules in 20 mg, convert the mass to grams and then to moles using the molar mass of glucose. Multiply the moles by Avogadro's number to get approximately 6.68 × 1019 molecules.

Step-by-step explanation:

To calculate the number of glucose molecules in 20 mg of glucose, we use Avogadro's number, which tells us that one mole of any substance contains 6.022 × 1023 molecules.

The molar mass of glucose (C6H12O6) is approximately 180.16 g/mol.

First, convert 20 mg to grams:

20 mg = 0.02 g

Now, we determine the number of moles in 0.02 g of glucose:

0.02 g × (1 mol / 180.16 g) = 1.11 × 10-4 mol

The number of molecules in 1.11 × 10-4 moles of glucose is:

1.11 × 10-4 mol × (6.022 × 1023 molecules/mol) = 6.68 × 1019 molecules