JEE Main Physical Chemistry — Energetics & Equilibrium: Chemical Thermodynamics – Chapter Test
JEE Main Physical Chemistry — Energetics & Equilibrium: Chemical Thermodynamics – Chapter Test is an online chapter test in the JEE Main pattern, covering Physical Chemistry — Energetics & Equilibrium. Attempt it on SeatBeat with a timer like the real exam, then see a detailed solution for every question and your score and weak-topic analysis.
Topics in this test
| Topic | Questions |
|---|---|
| Physical Chemistry — Energetics & Equilibrium | 20 |
Difficulty: 9 medium · 11 hard
Chemical Thermodynamics MCQ questions with answers
The first 3 of 20 questions. Unlock the series for the rest, each with a solution.
Q1. According to the IUPAC sign convention, the mathematical statement of the first law of thermodynamics for a closed system is best written as which of the following, where q is heat and w is work?
IUPAC चिह्न परिपाटी (sign convention) के अनुसार, एक बंद निकाय (closed system) के लिए ऊष्मागतिकी के प्रथम नियम का गणितीय कथन निम्नलिखित में से किस रूप में सर्वोत्तम ढंग से लिखा जाता है, जहाँ q ऊष्मा है और w कार्य है?
- A. ΔU = q − w, with w = work done on the system / ΔU = q − w, जहाँ w = निकाय पर किया गया कार्य
- B. ΔU = −q − w, with w = work done by the system / ΔU = −q − w, जहाँ w = निकाय द्वारा किया गया कार्य
- C. ΔU = q + w, with w = work done on the system / ΔU = q + w, जहाँ w = निकाय पर किया गया कार्य
- D. ΔU = w − q, with q = heat released by the system / ΔU = w − q, जहाँ q = निकाय द्वारा मुक्त की गई ऊष्मा
Solution
By the IUPAC convention, ΔU = q + w, where w is the work done ON the system (so w is positive when the surroundings do work on the system). Heat absorbed by the system is taken as positive.
IUPAC परिपाटी के अनुसार, ΔU = q + w, जहाँ w निकाय पर किया गया कार्य है (अतः जब परिवेश निकाय पर कार्य करता है तो w धनात्मक होता है)। निकाय द्वारा अवशोषित ऊष्मा को धनात्मक लिया जाता है।
Q2. Which one of the following species does NOT have a standard enthalpy of formation equal to zero at 298 K?
निम्नलिखित में से किस एक स्पीशीज़ की 298 K पर मानक संभवन एन्थैल्पी शून्य के बराबर नहीं है?
- A. Br₂(l)
- B. Hg(l)
- C. Br₂(g)
- D. N₂(g)
Solution
The reference form of bromine at 298 K is liquid Br₂, so ΔfH° of Br₂(g) is not zero (it equals the enthalpy of vaporization, about +31 kJ mol⁻¹), whereas Br₂(l), Hg(l) and N₂(g) are the stable standard-state forms of their elements and are assigned zero.
298 K पर ब्रोमीन का संदर्भ रूप द्रव Br₂ है, अतः Br₂(g) की ΔfH° शून्य नहीं है (यह वाष्पन एन्थैल्पी के बराबर है, लगभग +31 kJ mol⁻¹), जबकि Br₂(l), Hg(l) और N₂(g) अपने तत्वों के स्थायी मानक-अवस्था रूप हैं और इन्हें शून्य मान दिया जाता है।
Q3. For ice, the enthalpy of fusion at 0 °C is 6.0 kJ mol⁻¹ and the enthalpy of vaporization of water at the same temperature is 45.0 kJ mol⁻¹. By Hess's law, the enthalpy of sublimation of ice at 0 °C is:
बर्फ के लिए 0 °C पर गलन एन्थैल्पी 6.0 kJ mol⁻¹ है तथा उसी ताप पर जल की वाष्पन एन्थैल्पी 45.0 kJ mol⁻¹ है। हेस के नियम द्वारा, 0 °C पर बर्फ की ऊर्ध्वपातन एन्थैल्पी है:
- A. 39.0 kJ mol⁻¹
- B. 45.0 kJ mol⁻¹
- C. −51.0 kJ mol⁻¹
- D. 51.0 kJ mol⁻¹
Solution
Sublimation (solid → vapour) can be carried out as fusion followed by vaporization, so ΔsubH = ΔfusH + ΔvapH = 6.0 + 45.0 = 51.0 kJ mol⁻¹.
ऊर्ध्वपातन (ठोस → वाष्प) को गलन और उसके बाद वाष्पन के रूप में सम्पन्न किया जा सकता है, अतः ΔsubH = ΔfusH + ΔvapH = 6.0 + 45.0 = 51.0 kJ mol⁻¹।
Frequently asked questions
How many questions are in the JEE Main Physical Chemistry — Energetics & Equilibrium: Chemical Thermodynamics – Chapter Test?
20 questions for 20 marks, to be answered in 20 minutes.
Is there negative marking in the JEE Main Physical Chemistry — Energetics & Equilibrium: Chemical Thermodynamics – Chapter Test?
Yes — 0.25 marks are deducted for each wrong answer, as in the real exam pattern.
Which topics does the JEE Main Physical Chemistry — Energetics & Equilibrium: Chemical Thermodynamics – Chapter Test cover?
Physical Chemistry — Energetics & Equilibrium (20 questions).
Is the JEE Main Physical Chemistry — Energetics & Equilibrium: Chemical Thermodynamics – Chapter Test free?
It is part of the JEE Main 2027 Mock Test Series (104 tests, ₹299). You can first try Basic Concepts & Atomic Structure – Topic Test for free.
More tests in the JEE Main 2027 Mock Test Series
- Basic Concepts & Atomic Structure – Topic TestFree
- Bonding & Periodicity – Topic Test
- Inorganic — p/d/f Block & Coordination – Topic Test
- Organic — Biomolecules & Practical – Topic Test
- Organic — Functional Groups – Topic Test
- Organic — Fundamentals & Hydrocarbons – Topic Test
- Physical Chemistry — Electrochemistry & Kinetics – Topic Test
- Physical Chemistry — Energetics & Equilibrium – Topic Test
- Algebra — Combinatorics & Series – Topic Test
- Algebra — Numbers & Matrices – Topic Test
- Coordinate Geometry – Topic Test
- Differential Calculus – Topic Test
- Integral Calculus & Differential Equations – Topic Test
- Probability & Statistics – Topic Test
- Sets, Relations, Functions & Trigonometry – Topic Test
- Vectors & 3D Geometry – Topic Test
- Electrostatics and Current Electricity – Topic Test
- Magnetism, EMI and EM Waves – Topic Test
- Mechanics – Topic Test
- Modern Physics – Topic Test
- Optics – Topic Test
- Oscillations and Waves – Topic Test
- Properties of Matter & Heat – Topic Test
- Units, Measurement & Experimental Skills – Topic Test
- Basic Concepts & Atomic Structure: Atomic Structure – Chapter Test
- Basic Concepts & Atomic Structure: Some Basic Concepts in Chemistry – Chapter Test
- Bonding & Periodicity: Chemical Bonding and Molecular Structure – Chapter Test
- Bonding & Periodicity: Classification of Elements and Periodicity in Properties – Chapter Test
- Inorganic — p/d/f Block & Coordination: Coordination Compounds – Chapter Test
- Inorganic — p/d/f Block & Coordination: d- and f-Block Elements – Chapter Test
See the full JEE Main 2027 Mock Test Series → · JEE Main: pattern, notification & syllabus →