Question

Potassium superoxide, KO2, reacts with carbon dioxide to form potassium carbonate and dioxygen as follows: 4KO2+ 2CO2 -> 2K2CO3 + 3O2. This reaction makes potassium superoxide useful in a self-contained breathing apparatus.

a) Given th balance chemical equaition above, what is the mole relationship between KO2 and O2?

b)If you started with 0.250 mole of KO2 and 0.250 moles of CO2, which is your limiting reagent?

c) If an apparatus contains 2.50g KO2, how many grams of O2 is produced?

Answer 1

Ans :

a) 4 moles of KO2 produces 3 moles of O2

SO the mole relationship between KO2 and O2 is 4 : 3

b) 2 moles of CO2 requires 4 moles of KO2

So 0.250 moles of CO2 will require ( 0.250 x 4) /2 = 0.500 moles of KO2

So KO2 is the limiting reagent here.

c) The molar mass of KO2 = 71.1 g/mol

So 2.50 g = 2.50 / 71.1 = 0.035 moles

4 moles KO2 makes 3 moles O2

So 0.035 moles will make ( 0.035 x 3 ) / 4 = 0.02625 moles

The amount of O2 produced = 0.02625 x 32 = 0.84 grams