Question

iv) Calculate the number of moles in
(a) 56 g of He (b) 23 g of Na​

Answer 1

Answer:

Explanation:

(a) Molar mass of helium = 4g

Given mass = 56g

No. of moles = given mass / molar mass

No. of moles = 56g/4g

No. of moles = 14 moles

(b) Molar mass of sodium = 23g

Given mass = 23g

No. of moles = given mass / molar mass

No. of moles = 23g/3g

No. of moles = 1 mole

As we know,

1 mole of any substance contains =>

6.002*10^23 Atoms / molecules / ions.

Therefore 23 grams of sodium contains 6.002*10^23 Atoms.