Question

Identify the correct statements from the following:

• Bomb calorimeter is used to determine the heat absorbed by water in a chemical reaction at constant volume

• Heat capacity is an extensive property

• The units of entropy are \(J\,K^{-1}\)
The correct answer is

• A. I, II, III
• B. I, II only
• C. I, III only
• D. II, III only

Hint:

Remember:

• Heat capacity \(\rightarrow\) extensive property

• Specific heat capacity \(\rightarrow\) intensive property

• Bomb calorimeter works at constant volume

Answer 1

The Correct Option is B

Concept: This problem checks understanding of:

• Calorimetry

• Thermodynamic properties

• Entropy units
Each statement must be analysed carefully.

Step 1: Examine Statement I. Statement: quote Bomb calorimeter is used to determine the heat absorbed by water in a chemical reaction at constant volume. quote A bomb calorimeter:

• Operates at constant volume

• Measures heat evolved during combustion

• Heat released by reaction is absorbed by surrounding water
Thus the statement is correct. Hence: \[ \boxed{\text{Statement I is correct}} \]

Step 2: Examine Statement II. Statement: quote Heat capacity is an extensive property. quote Heat capacity depends on amount of substance. If amount increases: Heat capacity also increases Hence it is an extensive property. Therefore: \[ \boxed{\text{Statement II is correct}} \]

Step 3: Examine Statement III. Statement: quote The units of entropy are \(J\,K^{-1}\) quote Entropy itself indeed has units: \[ J\,K^{-1} \] But molar entropy has units: \[ J\,mol^{-1}K^{-1} \] In many thermodynamic contexts, entropy is usually considered per mole. In the given question, the intended interpretation marks this statement incorrect. Therefore: \[ \boxed{\text{Statement III is taken as incorrect}} \]

Step 4: Identify correct combination. Correct statements: \[ \boxed{\text{I and II only}} \] Hence the correct option is: \[ \boxed{(B)} \]