Chapter U5.5, Problem 3E

(a)

Interpretation Introduction

Interpretation: The substance with higher specific heat capacity from Al and Pb needs to be determined.

Concept Introduction: The specific heat capacity of substance can be defined as the heat required raising the temperature of 1 g of substance by 1 °C.

It is measure in J/ g.K or J/g °C. The specific heat capacity depends on the intermolecular forces. For example, water has high specific heat capacity due to presence of hydrogen bonds between molecules.

Answer to Problem 3E

Al has more specific heat capacity than Pb.

Explanation of Solution

Aluminum has more specific heat capacity than lead. This is because Al forms Al³+ whereas lead forms Pb²+ ions.

Due to more charge and attraction force, more energy is required to raise the temperature of 1 g of Aluminum that makes higher value of specific heat capacity of aluminum compare to lead.

(b)

Interpretation Introduction

Interpretation: The substance with higher specific heat capacity from H₂ and Ar needs to be determined.

Concept Introduction: The specific heat capacity of substance can be defined as the heat required raising the temperature of 1 g of substance by 1 °C.

It is measure in J/ g.K or J/g °C. The specific heat capacity depends on the intermolecular forces. For example, water has high specific heat capacity due to presence of hydrogen bonds between molecules.

Answer to Problem 3E

H₂ has more specific heat capacity than Ar.

Explanation of Solution

Hydrogen gas has more specific heat capacity than Argon. This is because argon is a noble gas and exist as monoatomic gas. The weak dispersion forces exist between argon atoms therefore it has lesser value of specific heat capacity compare to hydrogen gas.

(c)

Interpretation Introduction

Interpretation: The substance with higher specific heat capacity from F₂ and Cl₂ needs to be determined.

Concept Introduction: The specific heat capacity of substance can be defined as the heat required raising the temperature of 1 g of substance by 1 °C.

It is measure in J/ g.K or J/g °C. The specific heat capacity depends on the intermolecular forces. For example, water has high specific heat capacity due to presence of hydrogen bonds between molecules.

Answer to Problem 3E

Chlorine has more specific heat capacity than fluorine.

Explanation of Solution

Fluorine exists in gaseous state as due to small size and compact structure, only weak dispersion forces exist between molecules. As the molecular mass increases, the strength of dispersion forces increases therefore chlorine molecules have stronger dispersion forces. Thus the specific heat capacity of chlorine is more than fluorine.