[Kaspit]

Hello
Please help me, how I can recognize this reaction that take place under normal condition.

Really I'm not understanding how to approach for this question.

[Borek]

Will it be easier if the question was worded "Which of these reaction will not take place?"? Or "Which of these reactions are impossible?"?

[Babcock_Hall]

@OP,
Do you see any acid-base reactions in your list?  If so, what do you know about favorable acid-base reactions?

[Kaspit]

Ok
It's greate
I saw that all the correct answers ( a b d h) they have in the product acid or base.
But can you explain why it is? I'm not understand the correlation.
Thanks

[Babcock_Hall]

You have made a decent start, but there is still a ways to go yet.  I see at least one acid-base reaction in the original question that is not a, b, d, or h.  Therefore, it cannot be quite as simple as simply identifying all acid-base reactions and assuming that none of them occur.  After all, we know that some acid-base reactions do occur.  This leads back to the question I asked before.  What do you know about favorable acid-base reactions?  Also, not every reaction in the list is an acid-base reaction.

[Kaspit]

Ok
I know the classic acid base reaction.
Idon't know excectly what is "favorable acid base reaction"?
I would glad to know for which chemistry section this question belong.

[Babcock_Hall]

The word "favorable" often means that the equilibrium constant for the forward reaction is large (greater than one).  You may have heard a rule something like, "When the stronger acid and stronger base are the reactants and the weaker acid and the weaker base are the products, the equilibrium constant is large."  See whether or not you can apply this rule to some of your examples.