How many grams of Cl2 are needed to produce 2.4 grams of NaCl?
2Na + Cl2 2NaCl

The answer to your question is 1.46 g of Cl₂

Explanation:

Data

mass of Cl₂ = ?

mass of NaCl = 2.4 g

Chemical reaction

                              2Na  +  Cl₂  ⇒   2NaCl

Process

1.- Calculate the molar mass of chlorine and sodium chloride

Molar mass Cl₂ = 2 x 35.5 = 71 g

Molar mass of NaCl = 23 + 35.5 = 58.5 g

2.- Use proportions to solve this problem

                       71g of Cl₂ 2(58.5g) NaCl

                         x             2.4 g

                         x = (2.4 x 71) / 2(58.5)

                         x = 170.4 / 117

                         x = 1.46 g of Cl

fe 55.85 g/mol and h2o 18.02 g/mol.