1.7 Water Flashcards
What is a dipole molecule?
A molecule that has partially positive and partially negative parts
What is a hydrogen bond?
A type of weak bond formed between an electropositive hydrogen and an electronegative atom like oxygen or nitrogen
What is a polar solvent?
A solvent that is composed of molecules which contain dipoles and so have partially positive and partially negative parts
What is specific heat capacity?
The amount of energy needed to raise the temperature of a substance by a specific amount
What is surface tension?
A strong attraction of molecules at the surface of a fluid
What are 5 important properties of water that allow it to support life?
- It is polar
- It has a high specific heat capacity
- It reaches it’s maximum density at 4°C
- It is cohesive and adhesive
- It is incompressible
Why is it important that water is polar?
As this allows other polar substances to dissolve into it
Why is it important that water has a high specific heat capacity?
As this means that a lot of energy is required to make it change temperature, so organisms can survive in habitats such as the ocean, lakes and rivers as there is minimal fluctuation in their temperature throughout the year
Why it is important that water reaches it’s maximum density at 4°C?
As this means that ice is less dense than water, so floats above large bodies of it to provide an insulating layer for the organisms underneath, increasing their chances of survival in seasons like winter when temperatures drop
What are 2 reasons why is it important that water is cohesive and adhesive?
- As this allows water molecules to stick together and to the sides of transport tubes, meaning they can be transported easily in the xylem and phloem
- As cohesion allows for surface tension to occur by creating a high water-air boundary
Why is it important that water is incompressible?
As this allows it to be used in
hydraulic mechanisms inside animals and plants
