4. State and explain the following with an example .
a) Chemical combination
b) Chemical decomposion
c) Chemical displacement
d) Chemical double displacement
Answers
Answer:
(a) Combination reaction: A reaction in which two or more substances combine to form a single substance is called a combination reaction. A + B → AB e.g (i) When iron and sulphur are heated together, they combine to form iron sulphide. Fe + S + heat → FeS (ii) When carbon bums in oxygen to form a gaseous compound called carbon dioxide. C + O2 + heat → CO2 + heat (b) Decomposition reaction: A reaction in which a compound breaks up due to the application of heat into two or more simple substances is called decomposition reaction. AB + heat → A + B e.g. (i) Mercuric oxide when heated, decomposes to form two elements mercury and oxygen 2HgO(s) + heat → 2Hg(s) + O2(g) (ii) CaCO3, when heated, decomposes to calcium oxide and carbon dioxide. CaCO3 + heat → CaO + CO2 (c) Displacement reaction: A reaction in which a more active element displaces a less active element from a compound is called displacement reaction. AB + C → CB + A e.g. (i) Zinc, displaces copper from copper sulphate solution. Zn + CuSO4 (aq) → ZnSO4 (aq) + Cu (ii) Iron piece when added to copper sulphate solution, copper is displaced. Fe + CuSO4 → FeSO4 + Cu. (d) Double decomposition reaction: A chemical reaction in which two compounds in their aqueous state exchange their ions to form new compounds is called a double decomposition reaction. AB + CD → CB + AD e.g. (i) AgNO3 + HCl AgCl + HNO3(aq) (ii) NaOH (aq) + HCl (aq) NaCl (aq) + H2O.Read more on Sarthaks.com - https://www.sarthaks.com/160472/explain-following-types-chemical-reactions-giving-examples-each-combination-reaction
Answer:
State and explain the following with an example .
a) Chemical combination
b) Chemical decomposion
c) Chemical displacement
d) Chemical double displacement