CHEMISTRY

JAMB 2004 - Question 1

Chemistry 2004 JAMB Past Questions - Question 1: When a solid substance disappears completely as a gas on heating, the substance is said to have undergone

Choose the correct answers from the options given.
When a solid substance disappears completely as a gas on heating, the substance is said to have undergone
A:
B:
C:
D:
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Correct Answer

D

Explanation

When a solid substance disappears completely as a gas upon heating, the process is referred to as "sublimation." Sublimation is the phase transition in which a substance goes directly from a solid to a gas without passing through the liquid phase. This occurs when the temperature and pressure conditions are such that the substance's vapor pressure exceeds its triple point pressure. Common examples of substances that undergo sublimation include dry ice (solid carbon dioxide) and certain types of mothballs (such as naphthalene).