Q.3.92 - An Introduction to General, Organic, and Biological Chemistry

Question

The melting point of benzene is ${5.5}^{\circ }\mathrm{C}$ and its boiling point is ${80.1}^{\circ }\mathrm{C}$. Sketch a heating curve for benzene from $0^{o}C to {100}^{o}C$

a. What is the state of benzene at ${15}^{\circ }\mathrm{C}$?

b. What happens on the curve at $5.5^{o}C$?

c. What is the state of benzene at ${63}^{o}C$?

d. What is the state of benzene at ${98}^{o}C$?

e. At what temperature will both liquid and gas be present?

Step-by-Step Solution

Answer

The graph is shown

a. liquid state

b. It will be parallel to the x-axis

c. liquid state

d. gaseous state

e. both liquid and gas be present at $80.1^{o}C$

Step 1: Given Information

The melting point of benzene = $5.5^{o}C$

The boiling point of benzene = $80.1^{o}C$

Step 2: Explanation

The graph is,

Step 3: Explanation Part (a)

As per the temperature information given, the heating bend of benzene in the temperature range $0^{\circ }\mathrm{C}\text{ to }{100}^{\circ }\mathrm{C}$is drawn and from the bend, it is seen that the substance stays in a solid state up to and it began to liquefy at this temperature.

Subsequently at ${15}^{o}C$it will be in a liquid state.

Step 4: Explanation Part (b)

At the melting point of any substance, the heating bend stays parallel to the x-axis for example heat added as the temperature of the substance stays unaltered until entire the mass of the substance is melted.

Step 5: Explanation Part (c)

It will be in a liquid form at ${63}^{\circ }\mathrm{C}$ as the melting point of benzene is ${5.5}^{\circ }\mathrm{C}$ after which it turns liquid.

Step 6: Explanation Part (d)

It will be in a gaseous form at ${98}^{o}C$ as after reaching the boiling point it turns gaseous and the boiling point of benzene is ${80.1}^{\circ }\mathrm{C}$

Step 7: Explanation Part (e)

Both liquid and gas be present at ${80.1}^{\circ }\mathrm{C}$as both the states are present together as represented with a parallel line with the x-axis.