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

Answer: (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.
$H+CuO\stackrel{\Delta }{\to }{H}_{2}O+Cu$
$CuS{O}_4+5H_{2}o\to CuS{O}_4,5H_{2}O$
White Blue