[jessuh13]

Greetings,

I had the following question on a test:
Which of the following thermal decomposition reactions will require the highest temperature?
A. Ag₂O --> 2Ag + 1/2O₂
b. H₂O₂ --> H₂O + 1/2O₂
c. HgO --> Hg + 1/2O₂
d. Na₂O --> 2Na + 1/2O₂
e. PbO₂ --> PbO + 1/2O₂

I know the answer is D, but I do not understand why.
Could someone explain it to me?

Thanks in advance

[themonk]

You need to attempt to answer the question first.

Thermal decomposition is the use of heat to break down a chemical compound. So you want the reaction that needs the highest temperature (highest decomposition temperature).

Why is the answer D?

Your equations are already balanced, so what is the next step? Pull out a periodic table and think what information is usually given in one. Why are elements together? How strong are the bonds between the elements in each? What are their boiling points? These are some questions to get your mind rolling.