Water Flashcards
1
Q
What does polar mean?
A
- They have regions of negativity and positivity.
2
Q
Why is water polar?
A
- Water consists of 2 hydrogen atoms covalently bonded to one oxygen atom
- They share electrons
- Oxygen has a greater number of protons
- this means that the oxygen becomes slightly negative and the 2 hydrogen becomes slightly positive.
3
Q
How is water a liquid at room temperature?
A
- water molecules constantly move around
- make and break hydrogen bonds
- water is a liquid at room temp as the hydrogen bonds make it difficult for molecules to form a gas.
4
Q
How is water a good solvent?
A
- Water is polar
- cellular reactions can occur
- slightly negative end of a water molecule will be attracted to the positive ion - ions surrounded by water molecules
- they dissolve
5
Q
How is water less dense when its solid?
A
- polar nature of water
- water molecules in ice, forms 4 hydrogen bonds to other water molecules, spread out lattice
- this is less dense than liquid water so floats
6
Q
How does water have cohesion and surface tension?
A
- Cohesion is the force of attraction between molecules of the same type
- occurs due to the hydrogen bonds form
- water flows as one mass
7
Q
How can cohesion forces be seen on the surface of water?
A
- surface of water contracts, giving its ability to resist force
- called surface tension
8
Q
How does water have high specific heat capacity?
A
- hydrogen bonds between water absorb lots of energy
- takes a lot of energy to heat up
- water is stable - no temperature changes
9
Q
What is specific heat capacity?
A
- The energy needed to raise the temperature of 1g of water by 1 Celsius
10
Q
How does water have high latent heat of vaporisation/evaporation?
A
- a lot of energy is needed to break hydrogen bonds for it to turn from a liquid to gas
- lot of energy needed to be used up to make water evaporate
