Question

Purple Group Header Warm-Up Why can I smell a chocolate bar even though it is a solid? Read the description of the office mystery and write your prediction below. On a warm afternoon, a Universal Space Agency office worker returned from lunch break and noticed the office smelled like chocolate. She didn't see anything in the air, but she noticed her coworker was opening the wrapper of a solid bar of chocolate. Why can the office worker smell the chocolate bar even though it is in solid form?

Answer 1

The office worker can smell the chocolate bar because its aroma compounds are released into the air and sensed by the olfactory receptors in the nose. This process of scent dispersion is due to the volatility of the molecules, which vaporize and spread through the air, especially when warmed.

Step-by-step explanation:

• The office worker can smell the chocolate bar even though it is a solid because of the way smell works.
• Solids like chocolate can release aroma compounds into the air, especially when warmed, which are then picked up by the nose.
• Similarly, when trying to learn about a new material, chemists often rely on smell as a key observation, without the need to taste, which is unsafe for chemical substances.

• When materials are heated, like chocolate in a warm office or during handling, they often release more scent molecules into the atmosphere.
• These molecules are volatile, which means they can vaporize and disperse through the air at room temperature, reaching our olfactory receptors and giving us the sensation of smell.
• This is the same reason you can smell a candle or food cooking even if you're not in direct contact with the source.

Answer 2

The smell of a chocolate is from the presence of volatile compounds present in the chocolate bar which at room temperature readily changes phase from solid to liquid to vapor or gas

Step-by-step explanation:

There are nearly 600 identified compounds present in a chocolate bar and out of these, there are volatile components which gives the chocolate bar its distinctive aroma.

These volatile chocolate contents readily change phase from solid to vapor, with very short duration liquid phase.

For example, 3 methylbutanal, vanillin, and several organic compounds which are known to be readily volatile.