D And F Block Elements Question 5
Question 5 - 2024 (27 Jan Shift 1)
$NaCl$ reacts with conc. $H _2 SO _4$ and $K _2 Cr _2 O _7$ to give reddish fumes (B), which react with $NaOH$ to give yellow solution (C). (B) and (C) respectively are ;
(1) $CrO _2 Cl _2, Na _2 CrO _4$
(2) $Na _2 CrO _4, CrO _2 Cl _2$
(3) $CrO _2 Cl _2, KHSO _4$
(4) $CrO _2 Cl _2, Na _2 Cr _2 O _7$
Show Answer
Answer (1)
Solution
$NaCl+$ conc. $H _2 SO _4+K _2 Cr _2 O _7 \rightarrow CrO _2 Cl _2+KHSO _4+NaHSO _4+H _2 O$
(B)
Reddish brown
$CrO _2 Cl _2+NaOH \rightarrow Na _2 CrO _4+NaCl+H _2 O$
(C)
Yellow colour
