biological molecules- water

Question 1

Give the definition of specific heat capacity

Answer 1

The amount of energy needed to raise the temperate of an amount of substance by 1 degree

Question 2

Water has a high specific heat capacity, why is this important?

Answer 2

High SHC means that water requires large amounts of energy to heat, which minimises temp fluctuations and provides thermal stability

Question 3

water is a good reactant, what is another name for this

Answer 3

Metabolite

Question 4

why is having a relatively high latent heat of vaporisation important for water?

Answer 4

The evaporation of water provides a cooling effect with little water loss

Question 5

water is a polar molecule, give the reason for this.

Answer 5

There is an uneven distribution of positive and negative charge between hydrogen and oxygen molecules

Question 6

Why does water have a high specific heat capacity?

Answer 6

Strong hydrogen bonds which can absorb large volumes of energy

Question 7

how are hydrogen bonds formed?

Answer 7

By a very electronegative atom of a polar molecule and a hydrogen atom

Question 8

Ice is less dense than water , Why is this?

Answer 8

As water looses energy, H- bonds hold molecules in fixed positions further apart

Question 9

At what temperature is water most dense?

Answer 9

4 degrees

Question 10

Why is ices denisty an advantage to aquatic species

Answer 10

Ice prevents water freezing bottom up therefore creating insulation

Question 11

What is cohesion?

Answer 11

hydrogen bonds allowing water molecules to ‘stick’ together, this enables the flow and transport of water

Question 12

give 2 examples of cohesion

Answer 12

water moving up xylem tissues for transpiration

Question 13

why does surface tension occur

Answer 13

Strong cohesion as a result of strong hydrogen bonds resisting the breaking of the surface