Standard enthalpy of vaporisation Δvap H⁰ for water at 100⁰C is 40.66 kJ mol⁻¹.

Standard Enthalpy Of Vaporisation Vap H For Water At 100c Chemistry Question

Standard enthalpy of vaporisation Δvap H⁰ for water at 100⁰C is 40.66 kJ mol⁻¹. The internal energy of vaporisation of water at 100⁰C (in kJ mol⁻¹) is

Options

(a) 37.56
(b) -43.76
(c) 43.76
(d) 40.66

Correct Answer:

37.56

Explanation:

ΔvapH⁰ = 40.66 kJ mol⁻¹,
T = 100 + 273 = 373K,
ΔE = ? , ΔH = ΔE + Δn(g)RT ⇒
ΔE = ΔH – Δn(g) RT,
Δn(g) = number of gaseous moles of products – number of gaseous moles of reactants, H₂O(l) ⇌ H₂O(g), Δn(g) = 1 – 0 = 1, ΔE = ΔH -RT , ΔE = ( 40.66 X 10³) – (8.314 X 373), ΔE = 37559 J/mol or 37.56 kJ/mol.

Related Questions:

  1. The number of structural isomers possible from the molecular formula C₃H₉N is
  2. Which pair of atomic numbers represents s-block elements?
  3. Aqueous solution of which of the following compounds is the best conductor
  4. When acetone reacts with bleaching powder, the compound formed is
  5. In which one of the following molecules the central atom does not have sp³

Topics: Thermodynamics (179)
Subject: Chemistry (2512)

Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score

18000+ students are using NEETLab to improve their score. What about you?

Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.

NEETLab Mobile App

Share this page with your friends

Be the first to comment

Leave a Reply

Your email address will not be published.


*