Question

The stoichiometric constants for the reaction $pCu+qHN{O}_3\to rCu(N{O}_3{)}_2+sNO+t{H}_{2}O$ $p,q,r,s$ and $t$ respectively are:

• A. 3, 3, 3, 2, 3
• B. 3, 2, 3, 2, 4
• C. 3, 8, 3, 2, 4
• D. 2, 3, 3, 3, 2

Answer 1

The correct option is C 3, 8, 3, 2, 4

(Refer to Image)

$Cu⟶C{u}^{2+}+2e^{-}⟶\left(1\right)$

${N{O}_3}^{-}+4H^{+}+3e^{-}⟶NO+2H_{2}O⟶\left(2\right)$

$\left(1\right)\times 3,\left(2\right)\times 2$ & adding,

$3Cu⟶3C{u}^{2+}+6e^{-}$

${2N{O}_3}^{-}+8H^{+}+6e^{-}⟶2NO+4H_{2}O$

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$3Cu+{2N{O}_3}^{-}+8H^{+}⟶3C{u}^{2+}+2NO+4H_{2}O$

or, $3Cu+8HN{O}_3⟶3Cu(N{O}_3{)}_2+2NO+4H_{2}O$

$\therefore p,q,r,s$ & $t$ are $3,8,3,2$ & $4$ respectively.