Question

Consider the reaction shown.

4 HCl(g) + O₂(g) → 2Cl₂(g) + 2 H₂O(g)
Calculate the number of grams of Cl2, formed when 0.125 mol HCl reacts with an excess of 0₂.
mass:

Answer 1

4.43 g Cl₂

Step-by-step 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