Question

The presence of carbon in an organic compound is detected by heating it with:

• A. Sodium metal to convert it to $NaCN$
• B. $CaO$ to convert it into $CO$ which burns with a blue flame
• C. $CuO$ to convert it into $C{O}_2$ which turns lime water milky
• D. $Cu$ wire to give a bluish-green flame

Answer 1

The correct option is C $CuO$ to convert it into $C{O}_2$ which turns lime water milky

The given organic compound is mixed with dry copper oxide (CuO) and heated in a hard glass tube. The products of the reaction are passed over (white) anyhydrous copper sulphate and then bubbled through lime water. If copper sulphate turns blue due to the formation of $CuS{O}_4.5H_{2}O$ (by waer vapor) then the compound contains hydrogen. If lime water is turned milky by $C{O}_2,$ then the compound contains carbon.
The milkiness is due to $CaC{O}_3$