Question

Name a substance which, on heating, leaves behind no residue.

• A. Methane gas
• B. Ammonium nitrate
  
• C. Camphor
• D. All of the above
  

Answer 1

The correct option is D All of the above

Camphor is a very common substance that is known to sublime on heating. When camphor is heated, it changes directly from the solid state into the gaseous state and does not leave any residue behind.
Reaction:
$2C_{10}{H}_{16}O+27O_2\to 20C{O}_2+16H_{2}O$
Ammonium nitrate leaves no residue when heated:
$N{H}_{4}N{O}_3\to N_{2}O+2H_{2}O$
Methane gas leaves no residue on heating:
$C{H}_4+2O_2\to C{O}_2+H_{2}O$