How many chlorine molecules are there in 1.44g of this substance?

First, let’s determine how many moles of chlorine we are given in the problem.

To do this, divide the amount in grams by the weight of one mole of chlorine.

1.44: 71 = 0.02 (mol)

Then we multiply what we got by the number of molecules in one mole (Avogadro’s number)

0.02 x 6.02 x 10 (23 degrees) = 0.12 x 10 (23 degrees) molecules.