Skip main navigation

£199.99 £139.99 for one year of Unlimited learning. Offer ends on 28 February 2023 at 23:59 (UTC). T&Cs apply

Find out more

Example 1 : supercooled water

Exercise 1

If the system is insulated (adiabatic), -10℃ H({2})O((l)) (supercooled liquid) will be transformed to ice + liquid H({2})O at 0℃. Calculate fraction of ice in the final mixture.

      Basis : 1 mole of initial supercooled liquid.

  • Since the system is adiabatic, Qp=ΔHtotal=0.
  • In calculating enthalpy changes, take the reversible path. The enthalpy change of reversible path is the same with that of the original change since enthalpy is a state function.
  • Regard the process as follows.

  • Adiabatic : ΔHtotal=ΔH1+ΔH2=0

Meaning: the heat needed heating H2(l)from-10℃ to 0℃ is
provided by solidification of xmole of H2(l)from-10℃ to H2(s)0℃.
The latent heat is evolved from the solidification process.

This article is from the free online

Thermodynamics in Energy Engineering

Created by
FutureLearn - Learning For Life

Our purpose is to transform access to education.

We offer a diverse selection of courses from leading universities and cultural institutions from around the world. These are delivered one step at a time, and are accessible on mobile, tablet and desktop, so you can fit learning around your life.

We believe learning should be an enjoyable, social experience, so our courses offer the opportunity to discuss what you’re learning with others as you go, helping you make fresh discoveries and form new ideas.
You can unlock new opportunities with unlimited access to hundreds of online short courses for a year by subscribing to our Unlimited package. Build your knowledge with top universities and organisations.

Learn more about how FutureLearn is transforming access to education