Question

Complete the missing components/variables given as reactant and product in the following reactions:

(i) BaCl₂ + 'X' → +BaSO₄↓ 

(ii) Cu + AgNO₃→ Cu(NO₃)₂ + 'Y' 

(iii) CaCO₃ \(\overset{'Z'}\longrightarrow\) CaO + CO₂

Answer 1

(i) To get the missing component we have to think that in product we got sulphate salt (BaSO₄) so in reactant there must be some other sulphate must be present so that double displacement reaction could happen. 

So, the complete reaction is: 

BaCl₂ + ‘Na₂So₄’ → NaCl + BaSO₄↓ 

(ii) In this reaction, we can clearly see displacement reaction is taking place in which copper displaces silver nitrate and forms copper nitrate and silver. 

So, the complete reaction is: 

Cu + AgNO₃→ Cu(NO₃)₂ + 'Ag' 

(iii) We can guess after seeing this reaction that it must be decomposition reaction as a single reactant breaks into 2 products bus there is only one thing missing i.e. heat is not written on the arrow now it is thermal decomposition reaction. 

So, the complete reaction is

CaCO₃ \(\overset{heat}\longrightarrow\) CaO + CO₂