Potassium superoxide, KO2, is often used in oxygen masks (such as those used by firefighters) because KO2 reacts with CO2 to release molecular oxygen. Experiments indicate that 2 mol of KO2(s) react with each mole of CO2(g).
(a) The products of the reaction are K2CO3(s) and O2(g). Write a balanced equation for the reaction between KO2(s) and CO2(g).
(b) Indicate the oxidation number for each atom involved in the reaction in part (a). What elements are being oxidized and reduced?
(c) What mass of KO2(s) is needed to consume 18.0 g CO2(g)? What mass of O2(g) is produced during this reaction?

a:

b: Oxygen is the only element which is getting oxidised as well reduced

c: and

Explanation:

Part a: Balanced equation for the given reaction;

Rule:

step1 : first balance the metal

step2: Non metal except oxygen

step 3: lastly balance the oxygen

Part b: indicating oxidation number of each element both side

reactant side oxidation number:

K = +1

O= -0.5 and -2

C =+4

Product side oxidation number:

K = +1

O= 0 and -2

C =+4

From the above data it clearly that Oxygen is the only element which is getting oxidised as well reduced .

Part c: Mass calculation

from the balance equation it is clearly that 4 moles of need 2 moles of for complete reaction i.e. mole is used double the mole of

hence the mole of is two times of

From 2 mole of 3  mole of is produced

From 1 mole of 1.5  mole of is produced

From 0.41 mole of    mole of is produced

answer: - 3.) the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.

solution: - as per the rules, oxidation number of oxygen in its compounds is -2. the sum of oxidation numbers of all the elements of a molecule or compound is zero.

also, the oxidation number in elemental form is zero.

in no, the oxidation number of o is -2 so the oxidation number of n is +2 so that the sum is zero.

similarly, the oxidation number of c in co is +2 and o is -2.

on product side the oxidation number of n is 0 as it is in the elemental form() .

oxidation number of c in carbon dioxide is +4 as there are two oxygen in it and we know that each oxygen is -2.

so, oxidation number of n is changing from +2 to 0 and the oxidation number of c is changing from +2 to +4.

since nitrogen is reduced and hence no is acting as an oxidizing agent. carbon is oxidized and so co is acting as a reducing agent.

so, the right choice is number 3.)the oxidation state of nitrogen in no changes from +2 to 0, and the oxidation state of carbon in co changes from +2 to +4 as the reaction proceeds.