[INeedSerotonin]

X + H2O --> 2Y + 1/2 O2
2Y + H2SO4 --> Z + 2 H2O

X, Y e Z could be, respectively,

(A) CaO, Ca(OH)2 e CaSO4.
(B) Na2O, NaOH e Na2SO3.
(C) Na2O2, NaOH e Na2SO4. <---- this is the answer
(D) Al2O3, HalO2 e Al2 (SO4)3.
(E) K, KOH e K2SO4.

I know reactions with peroxides; so, if I add both equations, it is very easy to see which one is the answer: something plus acid will give us H2O2 plus something. This means that originally we had a peroxide, and putting acid on it gives us a salt plus H2O2.

But this is just a very small chapter on my book, and there is very little content about this on the internet. So I doubt that this is the only way to solve this exercise.

Can you guys see another way to solve it?

Thanks

[AWK]

little content about this on the internet

?

Na2O2 + 2H2O(cold) = H2O2 + 2NaOH

2Na2O2 + 2H2O(hot) = O2↑ + 4NaOH.

Na2O2 + 2HCl(diluted, cold) = 2NaCl + H2O2.

2Na2O2 + 2H2SO4 (diluted, hot) = 2Na2SO4 + 2H2O + O2↑.

Na2O2 + O2 = 2NaO2 (450-500°C, pressure).

2Na2O2 + S = Na2SO3 + Na2O (100° C)

2Na2O2 + С(graphite) = Na2CO3 + Na2O (100°C)

3Na2O2 + 2Al (powder) = 2NaAlO2 + 2Na2O (70-120°C).

2Na2O2 + 2 CO2 = 2Na2CO3 + O2

Na2O2 + CO = Na2CO3 (normal temp.).

Na2O2 + MnO2 = Na2MnO4 (400-500°C).

Na2O2 + 2Na = 2Na2O (130-200°C, in the atmosphere of Ar).

5Na2O2 + 8H2SO4(diluted) + 2KMnO4 = 5O2↑ + 2MnSO4 + 8H2O + 5Na2SO4 + K2SO4.

Na2O2 + 2H2SO4(diluted) + 2NaI = I2↓ + 2Na2SO4 + 2H2O.

3Na2O2 + 2Na3[Cr(OH)6] (hot) = 2 Na2CrO4 + 8NaOH + 2H2O.

Na2O2 + 2H2SO4 (diluted) + 2FeSO4 = Fe2(SO4)3 + Na2SO4 + 2H2O

Na2O2 + 2Fe(ОН)2(suspension) = 2FeO(OH)↓ + 2NaOH.

[INeedSerotonin]

Yeah, but those reactions are only achievable once you know the answer. In an exam, it's not possible just to research it on the internet.

If one googles "reactions with peroxides", there isn't much High School content that help to solve this specific exercise (with inorganic acids).

[AWK]

At least half of these reactions are learned at the beginning of studying chemistry.

[INeedSerotonin]

At least half of these reactions are learned at the beginning of studying chemistry.

I want to study this subject more thoroughly. Do you know where I can learn those reactions (the pattern it makes)? I tried googling "reactions with peroxides", but I only find Kharasch and anti-Markovnikoff. 

[AWK]

Google: SODIUM PEROXIDE Na2O2 reactions

[INeedSerotonin]

Google: SODIUM PEROXIDE Na2O2 reactions

Thanks. I wanted a more general approach (to include other metals too), but it seems that what works for sodium peroxide would work for potassium peroxide too.

So the most important reactions are the ones with peroxide + water and with peroxide + acid? Should I memorize the others (with graphite, oxygen, and so on) too for college exams, for example?

[AWK]

Hydrogen peroxide is a rather unstable chemical compound - quite stable only at lower temperatures (RT). Many substances decompose H₂O₂ catalytically (the most-known catalyst is MnO₂). In addition, H₂O₂ is a strong oxidant in acidic, alkaline and elevated temperatures. And the above reactions speak about it.

A huge amount of interesting information about H₂O₂ can be found at: http://www.h2o2.com/