Consider the reaction: N_2+3H_2\rightarrow 2NH_3  carried out at constant temperature and pressure. If \Delta H\; and \; \Delta U are the enthalpy and internal energy changes for the reaction, which of the following expressions is true?

  • Option 1)

    \Delta H=0\;

  • Option 2)

    \; \Delta H=\Delta U\;

  • Option 3)

    \; \Delta H< \Delta U\;

  • Option 4)

    \; \Delta H> \Delta U\;

 

Answers (1)

As we learnt in

First law of Thermodynamics -

Energy of universe is always conserved or total energy of an isolated system is always conserved

\Delta E= q + W


 

- wherein

\Delta E= Internal Energy

q= Heat

W= work

 

 \Delta H= \Delta U + \Delta nRT\ \; for\ N_{2}+3H_{2}\rightarrow 2NH_{3}

\Delta n_{g}=2-4=-2

\therefore \Delta H=\Delta U-2RT 

or    \Delta U\Delta H+2RT

\therefore \Delta U>\Delta H


Option 1)

\Delta H=0\;

This is incorrect option

Option 2)

\; \Delta H=\Delta U\;

This is incorrect option

Option 3)

\; \Delta H< \Delta U\;

This is correct option

Option 4)

\; \Delta H> \Delta U\;

This is incorrect option

Most Viewed Questions

Preparation Products

Knockout JEE Main April 2021 (One Month)

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Weekend Live Classes, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 14000/- ₹ 4999/-
Buy Now
Knockout JEE Main May 2021

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Weekend Live Classes, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 22999/- ₹ 9999/-
Buy Now
Test Series JEE Main May 2021

Unlimited Chapter Wise Tests, Unlimited Subject Wise Tests, Unlimited Full Mock Tests, Get Personalized Performance Analysis Report,.

₹ 6999/- ₹ 2999/-
Buy Now
Knockout JEE Main May 2022

Personalized AI Tutor and Adaptive Time Table, Self Study Material, Live Classes, Unlimited Mock Tests and Personalized Analysis Reports, 24x7 Doubt Chat Support,.

₹ 34999/- ₹ 24999/-
Buy Now
JEE Main Rank Booster 2021

Booster and Kadha Video Lectures, Unlimited Full Mock Test, Adaptive Time Table, 24x7 Doubt Chat Support,.

₹ 13999/- ₹ 6999/-
Buy Now
Boost your Preparation for JEE Main 2021 with Personlized Coaching
 
Exams
Articles
Questions