Verified Solution • 2025–26 Session moderate

QJEEM18Che02f: JEE Main 2018 Chemistry - Class 11 JEEM18Che02f Solution: An ideal gas undergoes a cyclic process as shown in Figure. Δ U …

An ideal gas undergoes a cyclic process as shown in Figure.

JEE Main 2018 (Online) 15th April Morning Slot Chemistry - Thermodynamics Question 160 English
ΔUBC = −5 kJ mol-1, qAB = 2 kJ mol-1, WAB = −5 kJ mol-1, WCA = 3 kJ mol-1. Heat absorbed by the system during process CA is :

Multiple Choice Options

  • A −5 kJ mol-1
  • B +5 kJ mol-1
  • C 18 kJ mol-1
  • D −18 kJ mol-1

Step-by-Step Verified Solution

Given,

ΔUBC = − 5 kJ/mol

ΔUAB = qAB + WAB

= 2 + (− 5)

= − 3 kJ/mol.

For cyclic process,

ΔU = 0

⇒ ΔUAB + ΔUBC + ΔUCA = 0

⇒ ΔUCA = −(−3) − (− 5) = 8 kJ/mol

As, ΔUCA = qCA + WCA

⇒ 8 = qCA + 3

⇒ qCA = + 5 kJ/mol.

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