Question

Some white colourless crystals are heated. A cracking sound is heard and brown fumes are given off. The residue is yellow-brown in colour. When a glowing splinter is held in fumes, is is relighted. The fumes consists of :

• A. $O_2$
• B. ${NO}_2$
• C. ${Cl}_2$
• D. ${NO}_2$ and $O_2$

Answer 1

Answer: (D)

${NO}_2$ and $O_2$

The yellow-brown fumes are characteristic of nitrogen dioxide. When a glowing splinter is held in fumes, is relighted. This indicates presence of oxygen gas. Thus, the fumes consists of ${NO}_2$ and $O_2$.