Question

In the detection of hydrogen from organic the compound, the compound is heated with CuO and water produced is tested with _______

• A. Lime water
• B. Anhydrous $CuS{O}_4$
• C. Potash solution
• D. Calcium chloride solution

Answer 1

The correct option is B Anhydrous $CuS{O}_4$

C and H are oxidized to $C{O}_2$ and $H_{2}O$ when heated with $CuO.$
$C{O}_2$ turns lime water milky and $H_{2}O$ turns anhydrous $CuS{O}_4$ to hydrated $CuS{O}_4$ which is blue in carbon.
$H+CuO\stackrel{△}{\to }{H}_{2}O+Cu$
$\underset{\text{White}}{CuS{O}_4}+5H_{2}O\to \underset{\text{Blue}}{CuS{O}_4.}5H_{2}O$