What alkali and alkaline earth metal oxides will turn moist red litmus blue and finally white? [closed]

How many of the following will turn moist red litmus blue and finally white?

$$\ce{Li2O}$$, $$\ce{KO3}$$, $$\ce{RbO2}$$, $$\ce{Cs2O2}$$, $$\ce{BeO}$$, $$\ce{MgO}$$, $$\ce{BaO2}$$, $$\ce{SrO}$$.

Since bleach convert moist red litmus blue and then white, but how we can identify which compound will act as bleach ?

The standard oxides $$\ce{Li2O, MgO}$$ and $$\ce{SrO}$$ are water soluble and hydrolyse to form hydroxides and a basic solution. $$\ce{BeO}$$ is insoluble in water.

$$\ce{RbO2}$$ is a superoxide which in aqueous solution undergoes disproportionation to $$\ce{O2}$$ and $$\ce{OH-}$$ so will give a blue litmus test.

The peroxides $$\ce{Cs2O2}$$ and $$\ce{BaO2}$$ react with water to give hydrogen peroxide and the hydroxides, so again a basic solution(source). The hydrogen peroxide produced will bleach the litmus paper.

$$\ce{KO3}$$(Potassium Ozonide) is highly unstable, decomposes in water to $$\ce{O2}$$ and $$\ce{KOH}$$

The oxides which will NOT decolorize litmus are $$\ce{Li2O, MgO, BeO}$$ and $$\ce{SrO}$$. The peroxides ($$\ce{Cs2O2}$$ and $$\ce{BaO2}$$), the superoxide($$\ce{RbO2}$$) and the ozonide($$\ce{KO3}$$) will decolorize litmus.

• KO3 is Potassium Ozonide – saket kumar Feb 11 '19 at 8:39
• RbO2 is technically a superoxide. – Oscar Lanzi Feb 11 '19 at 10:03
• @OscarLanzi quite correct, my error. I will correct the entry – Waylander Feb 11 '19 at 11:20
• @Waylander Can you mention Compound Name clearly which finally turn white ? I am asking this because in my book answer of this question is given as 4 I.e. 4 Compound will turn white finally. A/c to your answer only 3 compound will turn white. – saket kumar Feb 11 '19 at 12:55