Chemistry · 2026
JEE Main · 28 January 2026, Shift 2 · Q61
Consider the following reactions Na_2 B_4 O_7 → Δ 2 X + Y; CuSO_4+ Y → Non-Luminous flame Z + SO_3; 2 Z +2 X + Carbon → Luminous flame 2 Q + Na_2 B_4…
Consider the following reactions
$$\begin{aligned}
& \mathrm{Na}_2 \mathrm{~B}_4 \mathrm{O}_7 \xrightarrow{\Delta} 2 \mathrm{X}+\mathrm{Y} \\
& \mathrm{CuSO}_4+\mathrm{Y} \xrightarrow{\text { Non-Luminous flame }} \mathrm{Z}+\mathrm{SO}_3 \\
& 2 \mathrm{Z}+2 \mathrm{X}+\text { Carbon } \xrightarrow{\text { Luminous flame }} 2 \mathrm{Q}+\mathrm{Na}_2 \mathrm{~B}_4 \mathrm{O}_7+\mathrm{CO}
\end{aligned}
$$
The oxidation states of Cu in Z and Q, respectively are :
Official answer
From NTA’s final answer key for this paper.
(4)
$\displaystyle +2 \text { and }+1$
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JEE Main 2026 Chemistry question, with the answer from NTA’s final answer key. Where our answers come from.