Chemistry
A reaction of a type: AB + CD ⟶ AD + CB, involves
(i) no chemical change
(ii) decomposition of AB and CD
(iii) exchange of ions of AB and CD
(iv) combination of AB and CD
Answer
exchange of ions of AB and CD
Reason — In the type of reaction called double displacement two compounds exchange their positive and negative radicals.
Example : AB + CD ⟶ AD + CB
A new set of substances (AD and CB) is formed, so a chemical change definitely occurs. Decomposition means breaking a compound into simpler substances, which is not happening here. Combination means two substances combine to form one product, but here we get two new products.
Related Questions
A silvery white metal A is in the form of a ribbon. It burns with a dazzling white flame to form a white powder B. When water is added to powder B, it partially dissolves to form a substance C.
(a) What is metal A ?
(b) Write the equation for the conversion of A to B and state the type of reaction.
(c) Write a balanced equation for the conversion of B to C and state the type of reaction.
Which of the following is not a characteristic of a chemical change?
(i) It is irreversible
(ii) No net energy change is involved
(iii) New substance is formed
(iv) Involves absorption or liberation of energy
The reaction:
BaCl2 (aq) + H2SO4 (aq) ⟶ BaSO4 (s) + 2HCl (aq) is
(i) displacement reaction
(ii) neutralisation reaction
(iii) decomposition reaction
(iv) double displacement reaction
Thermal decomposition of sodium carbonate will produce
(i) carbon dioxide
(ii) oxygen
(iii) sodium hydroxide
(iv) no other product