Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions.

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Decomposition reactions are those in which a compound breaks down to form two or more substances. These reactions require a source of energy to proceed. Thus, they are the exact opposite of combination reactions in which two or more substances combine to give a new substance with the release of energy.

Decomposition reaction : $AB +$ Energy $\longrightarrow A + B$

$2{{H}_{2}}{{O}_{(l)}}\xrightarrow{\text{ Electroly}sis}2{{H}_{2(g)}}+{{O}_{2(g)}}$

Combination reaction : $A+B \longrightarrow A B+$ Energy

$2{{H}_{2(g)}}+{{O}_{2(g)}}\to 2{{H}_{2}}{{O}_{(l)}}\,+$ Energy

Similar Questions

Write the balanced chemical equation for the following and identify the type of reaction in each case.

$(a)$ Potassium bromide $(aq)$ $+$ Barium iodide$(aq)$ $\rightarrow$ Potassium iodide$(aq)$ $+$ Barium bromide$(s)$

$(b)$ Zinc carbonate$(s)$ $\rightarrow$ Zinc oxide$(s)$ $+$ Carbon dioxide$(g)$

$(c)$ Hydrogen$(g)$ $+$ Chlorine$(g)$ $\rightarrow$ Hydrogen chloride$(g)$

$(d)$ Magnestum $(s)$ $+$ Hydrochloric acid$(aq)$ $\rightarrow$ Magnesium chloride$(aq)$ $+$ Hydrogen $(g)$

What is a balanced chemical equation ? Why should chemical equations be balanced ?

Write the balanced equation for the following chemical reactions.

$(i)$ Hydrogen $+$ Chlorine $\to $ Hydrogen chloride

$(ii)$ Barium chloride $+$ Aluminium sulphate $\to $ Barium sulphate $+$ Aluminium chloride

$(iii)$ Sodium $+$ Water $\to $  Sodium hydroxide $+$ Hydrogen

Explain the "Oxidation'' in terms of gain or loss of oxygen with two examples.

Which of the statements about the reaction below are incorrect ?

$2 PbO _{( s )}+ C _{( s )} \longrightarrow 2 Pb _{( s )}+ CO _{2( g )}$

$(a)$ Lead is getting reduced.

$(b)$ Carbon dioxide is getting oxidised.

$(c)$ Carbon is getting oxidised.

$(d)$ Lead oxide is getting reduced.