A binary compound that forms when potassium reacts with oxygen has the composition 54.99% K and 45.01% O.This compound contains
A)one oxygen molecule and one potassium atom.
B)one peroxide ion and one potassium ion.
C)one superoxide ion and one potassium ion.
D)two oxide ions and one potassium ion.

Question

Quizplus · Accepted Answer

The given percentages of K and O in the compound suggest that the compound has the formula K2O2. This indicates the presence of superoxide ions, which contain the O2^- unit. So, option C, which has one superoxide ion and one potassium ion, is the best choice. Option A is incorrect because it suggests the presence of only one oxygen atom. Option B is incorrect because the compound has a 1:2 ratio of K and O, which is not possible for peroxide ions. Option D is incorrect because if the compound contained two oxide ions, its formula would be K2O, not K2O2.

A Binary Compound That Forms When Potassium Reacts with Oxygen