Medium
$A$ reddish-brown coloured metal, used in electrical wires, when powdered and heated strongly in an open china dish, its colour turns black. When hydrogen gas is passed over this black substance, it regains its original colour. Based on the above information, answer the following questions:
$(i)$ Name the metal and the black coloured substance formed.
$(ii)$ Write balanced chemical equations for both the reactions.
$(i)$ Name the metal and the black coloured substance formed.
$(ii)$ Write balanced chemical equations for both the reactions.
(N/A) $(i)$ The metal is copper $(Cu)$.
The black coloured substance formed is copper$(II)$ oxide $(CuO)$.
$(ii)$ The balanced chemical equations are:
Reaction $1$ (Oxidation of copper): $2Cu(s) + O_2(g) \xrightarrow{\Delta} 2CuO(s)$
Reaction $2$ (Reduction of copper oxide): $CuO(s) + H_2(g) \xrightarrow{\Delta} Cu(s) + H_2O(g)$
The black coloured substance formed is copper$(II)$ oxide $(CuO)$.
$(ii)$ The balanced chemical equations are:
Reaction $1$ (Oxidation of copper): $2Cu(s) + O_2(g) \xrightarrow{\Delta} 2CuO(s)$
Reaction $2$ (Reduction of copper oxide): $CuO(s) + H_2(g) \xrightarrow{\Delta} Cu(s) + H_2O(g)$
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Similar Questions
Identify the oxidising agent (oxidant) in the following reactions:
$(a) Pb_{3}O_{4} + 8HCl \longrightarrow 3PbCl_{2} + Cl_{2} + 4H_{2}O$
$(b) 2Mg + O_{2} \longrightarrow 2MgO$
$(c) CuSO_{4} + Zn \longrightarrow Cu + ZnSO_{4}$
$(d) V_{2}O_{5} + 5Ca \longrightarrow 2V + 5CaO$
$(e) 3Fe + 4H_{2}O \longrightarrow Fe_{3}O_{4} + 4H_{2}$
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$(a) Pb_{3}O_{4} + 8HCl \longrightarrow 3PbCl_{2} + Cl_{2} + 4H_{2}O$
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$(d) V_{2}O_{5} + 5Ca \longrightarrow 2V + 5CaO$
$(e) 3Fe + 4H_{2}O \longrightarrow Fe_{3}O_{4} + 4H_{2}$
$(f) CuO + H_{2} \longrightarrow Cu + H_{2}O$
Medium
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