Given the reaction:
c2h2 + 2h2 → c2h6
this reaction represents

Given  reaction: C2H2 + 2H2 → C2H6 This reaction represents: Combination reaction

Explanation:

When two or more substances react and form some new substance it is called as chemical reaction .

A + B --> C + D

(reactants )   (products )

Types of chemical reaction

we come across different types of reactions that occur in nature .

Out of them , combination is also one type

Combination reaction

It is a reaction ,when two or more reactants react to form single product .

i.e A+BAB(IN THIS ONE SINGLE PRODUCT IS FORMED )

This  reaction can be between element element , element compound or compound compound .  

LIKE : H₂+Cl₂HCL

         (E)    (E)         (PRODUCT )

           SO₂+O₂SO₃

             ©   (E)        (PRODUCT )

           CO₂+H₂OH₂CO₃

In the above asked equation :

C₂H₂ + 2 H₂ --> C₂H₆

The ethane is formed by combination reaction This reaction obeys law of conservation of mass as it is balanced .

Sorry i dont understand the question can you rephase it?

Hbr dissociates to form h+ and br-ca(oh)2 dissociates to form ca2+ and 2oh-the h+ and oh- react to form waterassuming the reactants are dissolved in water, the net reaction is h+ + oh- —> h2oif you’re asked to show all components of the reaction, the complete reaction is 2hbr + ca(oh)2 —> cabr2 + 2h2o