Summary
Summary OCR A/AS-Level Biology 2.2.2 Water and Its Properties
Revision summary of key knowledge from OCR A/AS-Level Biology 2.2.2 Water and Its Properties.
[Show more]
Connected book
Book Title:
Author(s):
- Edition:
- ISBN:
- Edition:
Seller
Follow
Content preview
Water and its PropertiesStructure and Polarity
Water is made of two hydrogen atoms covalently bonded to one oxygen atom. The oxygen
atom has a slightly greater amount of protons in its nucleus so exerts a greater attraction for
electrons. This makes water a polar molecule since the oxygen has a slightly negative charge
(δ˗) and the hydrogen atoms have a slightly positive charge (δ˖).
Properties
Separate water molecules join together by hydrogen bonds formed by the attraction between
slightly positive hydrogen atoms and slightly negative oxygen atoms. These hydrogen bonds
give water 3 properties:
Cohesiveness – the ability of water molecules to ‘stick’ together
Adhesiveness – the ability of water molecules to ‘stick’ to other polar molecules
Good solvent – water molecules surround polar molecules to break them down easily
Water is unique since it is less dense as a solid than as a liquid and it expands upon freezing.
This is because as water the hydrogen bonds are constantly braking and re-forming enabling a
more dense spacing, whereas as ice, the maximum amount of hydrogen bonds are formed
causing the molecules to be further apart
Heat Properties
Water has the highest heat capacity of all liquids, so it requires a lot of energy to change
temperature and hence heats up and cools down very slowly. This allows large bodies of water
maintain a relatively stable temperature and makes water a good temperature regulator.
Water also has a high latent heat of vaporisation meaning it requires a lot of energy to
evaporate. This gives water an excellent cooling effect as it draws this energy as thermal
energy from the surface it is on. Many organisms utilise this through sweating.
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller izzylewington04. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £2.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
83662 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now