Answer:
0.0200 moles
Explanation:
From the periodic table, we find the molecular weight of Cl2 gas to be 70.9 grams/mole. To convert 1.42g to moles:
(1.42g Cl2)/(70.9 grams/mole)
grams cancel and moles moves to the top
(1.42g Cl2)/(70.9 grams/mole) = 0.0200 moles to 3 sig figs