Question

Consider the reaction shown.

Answer 1

Answer:

4.43 g Cl₂

Explanation:

To find the mass of Cl₂, you need to (1) convert moles HCl to moles Cl₂ (via the mole-to-mole ratio from equation coefficients) and then (2) convert moles Cl₂ to grams (via the molar mass). It is important to arrange the conversions/ratios in a way that allows for the cancellation of units. The final answer should have 3 significant figures like the given value.

4 HCl(g) + O₂(g) -----> 2 Cl₂(g) + 2 H₂O(g)
^                                   ^

Molar Mass (Cl₂): 2(35.453 g/mol)

Molar Mass (Cl₂): 70.906 g/mol

0.125 moles HCl          2 moles Cl₂             70.906 g
--------------------------  x  ----------------------  x  -------------------  =  4.43 g Cl₂
                                     4 moles HCl              1 mole