Question

calculate no. of moles in 18 g of glucose

Answer 1

180g of glucose is 1mol
Number of moles in 18g of glucose = 18/180 = 0.1 mol

Answer 2

Given:

The mass of glucose = 18g

To Find:

The number of moles of glucose

Solution:

The number of moles of a substance with molecular mass M and given sample mass m is given by m / M.

The molecular formula of glucose is C₆H₁₂O₆

The molecular mass of glucose = 6 X Molecular mass of C + 12 X Molecular mass of H + 6 X Molecular mass of O

We know that

Molecular mass of C = 12g

Molecular mass of H = 1g

Molecular mass of O = 16g

⇒ Molecular mass of glucose = 6 X 12 + 12 X 1 + 6 X 16

= 72 + 12 + 96

= 180g

∴ The number of moles = 18/ 180 = 0.1

Hence, 0.1 moles of glucose are presnent in 18g sample of glucose.