properties of water Flashcards
what is water made up of?
2 hydrogen atoms and 1 oxygen atom (H20)
how are is H20 bonded?
through covalent bonds
does water have a neutral charge?
yes. h=+1, 0–2
what is a polar molecule?
where the sharing of electrons between atoms is uneven
is water a polar molecule or a non-polar molecule?
water is a polar molecule because the sharing of electrons between the hydrogen and oxygen atoms is uneven
which atom in H20 attracts more electrons?
oxygen
in water, which atom has a weak negatively charged region and a weak positively charged region?
the oxygen atom has a weak negatively charged region as it attracts electrons more strongly compared to the hydrogen atom. this leaves the hydrogen atom with a weak positively charged region
what bonds form between water molecules?
hydrogen bonds
why are hydrogen bonds constantly breaking and reforming?
because they are weak
where are the hydrogen bonds formed in joined water molecules?
between the negatively and positively charged regions of adjacent water molecules (a - O atom and a +H atom)
what are the main 7 properties of water?
- a good solvent
- a high specific heat capacity
- less dense as a solid
- a high latent heat of vaporisation
- a reagent
- a polar molecule
- cohesion/adhesion
what is meant by water being a good solvent?
many substances can dissolve in it
is water a good solvent?
yes
why is it good that water is a good solvent?
more chemical reactions can occur within cells as dissolved substances are more chemically reactive
ions and polar molecules cannot dissolve in water. true or false?
false. ions and polar molecules can dissolve in water
what is meant by the term ‘specific heat capacity’?
the amount of energy needed to raise the temperature of 1kg of a substance by 1 Degree Celsius
does water have a low or high specific heat capacity?
a high one
why does water require a lot of energy to raise its temperature?
due to the many hydrogen bonds between molecules
what are the benefits of water having a high specific heat capacity?
its temperature isn’t risen easily, meaning it is a good habitat and can can maintain enzyme activity. it is also in blood plasma so it can transfer heat as it easily absorbs it without being effected
what does it mean if a substance has a high latent heat vaporisation?
in order to change state from liquid to gas a large amount of thermal energy must be absorbed
why does water have a high latent heat vaporisation?
a lot of energy needs to be absorbed to break the hydrogen bonds between molecules
why is water having a high latent heat vaporisation good for organisms?
it means only a small amount of water needs to evaporate to lose a lot of heat, so it acts as a coolant
why does water become less dense as a solid?
the hydrogen bonds fix the position of the polar molecules slightly further apart than in the liquid state
what is meant by the term adhesion?
molecules are attracted to other molecules
