When potassium is heated in an iron deflagrating spoon until it ignites and then lowered in dry jars of oxygen, it burns with bright lilac flame forming orange-yellow solid higher oxides (e.g. potassium peroxide, K2O2, and potassium dioxide, KO2).
2 K + O2 ==> K2O2
K + O2 ==> KO2
When these substances are dissolved in water, oxygen is evolved and an alkaline solutions, containing potassium hydroxide, which turn red litmus blue is formed.>
2 K2O2 + 4 H2O ==> 4 KOH + O2
4 KO2 + 2H2O ==> 4 KOH + 3 O2