If three moles of an ideal gas at 300 K expand isothermally from 30 dm3 to 45 dm3 against a constant opposing pressure of 80 kPa, then the amount of heat transferred is ______ J.
Correct Answer: 1200
Solution and Explanation
Using the first law of thermodynamics:
\[ \Delta U = Q + W \]
For an isothermal process, \(\Delta U = 0\), so \(Q = -W\).
\[ W = -P_{\text{ext}} \Delta V = -80 \times 10^3 \times (45 - 30) \times 10^{-3} = -1200 \, \text{J} \]
Top Questions on Thermodynamics
- At 298K, if the standard Gibbs energy change \(\Delta_r G^\circ\) of a reaction is - 115 kJ, the value of \(\log_{10} K_p\) will be (\(R = 8.314 \text{ J K}^{-1}\text{mol}^{-1}\))
- TS EAMCET - 2025
- Chemistry
- Thermodynamics
- Three moles of an ideal gas undergoes a cyclic process ABCA as shown in the figure. The pressure, volume and absolute temperature at points A, B and C are respectively \((P_1, V_1, T_1)\), \((P_2, 3V_1, T_1)\) and \((P_2, V_1, T_2)\). Then the total work done in the cycle ABCA is (R- Universal gas constant).
- TS EAMCET - 2025
- Physics
- Thermodynamics
The standard heat of formation, in kcal/mol, of $Ba^{2+}$ is:
Given: Standard heat of formation of SO₄²⁻(aq) = -216 kcal/mol, standard heat of crystallization of BaSO₄(s) = -4.5 kcal/mol, standard heat of formation of BaSO₄(s) = -349 kcal/mol.- NEET (UG) - 2025
- Chemistry
- Thermodynamics
- Which of the following materials belongs to diathermanous substance?
- Maharashtra Class XII - 2025
- Physics
- Thermodynamics
- In a thermodynamic system, define -- (a) Mechanical equilibrium (b) Chemical equilibrium and (c) Thermal equilibrium
- Maharashtra Class XII - 2025
- Physics
- Thermodynamics
Questions Asked in JEE Main exam
Let \( S = \left\{ m \in \mathbb{Z} : A^m + A^m = 3I - A^{-6} \right\} \), where
\[ A = \begin{bmatrix} 2 & -1 \\ 1 & 0 \end{bmatrix} \]Then \( n(S) \) is equal to ______.
- JEE Main - 2025
- Matrix Algebra
- Let \( a_1, a_2, a_3, \dots \) be a G.P. of increasing positive terms. If \( a_1 a_5 = 28 \) and \( a_2 + a_4 = 29 \), then the value of \( a_6 \) is equal to:
- JEE Main - 2025
- Sequences and Series
Let \( T_r \) be the \( r^{\text{th}} \) term of an A.P. If for some \( m \), \( T_m = \dfrac{1}{25} \), \( T_{25} = \dfrac{1}{20} \), and \( \displaystyle\sum_{r=1}^{25} T_r = 13 \), then \( 5m \displaystyle\sum_{r=m}^{2m} T_r \) is equal to:
- JEE Main - 2025
- Arithmetic and Geometric Progressions
- In a group of 3 girls and 4 boys, there are two boys \( B_1 \) and \( B_2 \). The number of ways in which these girls and boys can stand in a queue such that all the girls stand together, all the boys stand together, but \( B_1 \) and \( B_2 \) are not adjacent to each other, is:
- JEE Main - 2025
- Permutations
- A 400 g solid cube having an edge of length \(10\) cm floats in water. How much volume of the cube is outside the water? (Given: density of water = \(1000 { kg/m}^3\))