Which of the following reactions will be considered as a double displacement reaction?

Correct option is D

Sol: The correct answer is (d) $$HCl + KOH → KCl + H_2O$$

​​In a double displacement reaction, the ions of two compounds exchange places to form two new compounds

Option A- $$H _2​ CO _3​ →CO _2​ +H _2​ O$$

​​Type of reaction:Decomposition Reaction

• ​This is a decomposition reaction, where one reactant (carbonic acid, $$H_2CO_3$$​ )H2CO3H_2CO_3 breaks down into two products: carbon dioxide $$(CO_2)$$​ and $$(H_2O)$$​ water . There is no exchange of ions between two compounds​

Option B- $$MgO+H _2​ O→Mg(OH) _2​$$

​​Type of reaction:Combination Reaction

• This is a combination reaction, where magnesium oxide (MgO) combines with water $$(H_2O)$$ to form magnesium hydroxide ( $$Mg(OH)_2$$) Again, no exchange of ions occurs between two compounds. The reaction involves the combination of two reactants to form a single product

Option C- $$Zn+FeCl _3​ →ZnCl _2​ +Fe$$

​​Type of reaction:Single Displacement Reaction

• In this reaction, zinc (Zn) displaces iron (Fe) from iron chloride $$(FeCl_3)$$ to form zinc chloride $$(ZnCl_2)$$ and iron. This is a single displacement (or single replacement) reaction, where one element replaces another in a compound. Since there is no exchange of ions between two compounds
  

Option D- $$HCl+KOH→KCl+H _2​ O$$

​​Type of reaction:Double Displacement Reaction

This is a double displacement reaction (also known as a precipitation reaction or neutralization reaction). In this reaction:

• The $$H^+$$ion from hydrochloric acid (HCl) reacts with the $$OH^-$$ ion from potassium hydroxide (KOH) to form water $$(H_2O)$$ ​​
  
• ​The $$K^+$$ ion from potassium hydroxide combines with the $$Cl^-$$ ion from hydrochloric acid to form potassium chloride (KCl).This involves the exchange of ions between two compounds, which is the characteristic of a double displacement reaction.​