Question

Question is in attachment.

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Answer 1

$\large\color{lime}\boxed{\colorbox{black}{Answer : - }}$

( C )

$2CuO+Cu₂S - - - - > 4Cu+ SO₂$

$Cu + HNO_3 → Cu(NO_3)_2 - -- ^{NH_3} -- > [Cu(NH_3)_4] ^{2 + }$

$CUCO_3 - - - > CuO + CO₂$

$CO₂ + Ca(OH)₂ →→→ CaCO_3 - - ^{CO₂ + H₂O} - > Ca(HCO_3)_2$

Answer 2

You don't need enough chemistry knowledge for solving this.

As we know that adding $CO_2$ with lime water turns it milky (formation of $CaCO_3$)

Look at S, we have $Ca(OH)_2$ turning milky.

The only thing responsible for that is $CO_2$

Only option C has $CO_2$.

Lol, sometimes you require mental ability more than chemistry ; )