Water Flashcards
What causes a polarised molecule?
unequal sharing of electrons which causes an uneven charge distribution (the element H is bonded to may be more electronegative e.g. O which means it attracts more electrons , causing unequal sharing of electrons
What makes water a polarised molecule?
It has a region of slight positive charge(the H atoms) and a region if slight negative charge(the O atom)because it shares electrons unequally in a covalent bond, the shared electrons are more attracted to the O because it has more protons than the H=opposites attract. Due to this, O is more electronegative than H .
Whats a hydrogen bond?
a weak interaction between a H atoms bonded to two electronegative atoms.
How many water molecules form one H bond
two , they are found between the hydrogen atom of one water molecule and the oxygen atom of another adjacent water molecule.
What are three features of H bonds?
-They are weaker than covalent bonds but they are stronger than van der waals forces=Strength.
- In liquids they constantly break and reform due to thermal motion=Dynamic nature.
-They stabilise polymers(100s and 1000s of them form between chains of monomers).
How do salts(e.g.CuSO4) dissolve in water?
the positive Cu ions are attracted to the slightly negative O atom and the negative sulphate ions are attracted to the slightly positive H atoms(search up a diagram).
What property of water has the definition: water molecules can bind to each other
cohesion
How does cohesion help organisms?
Eukaryotes-cohesion allows water to travel up a plant against gravity(in the xylem).Cohesion makes surface tension which helps water striders skate on water.
What property of water has the definition: water molecules can stick to other surfaces.
adhesion
How does adhesion help living organisms?
Eukaryotes-adhesion allows water molecules sick to the walls of the xylem and travel up a plant against gravity.
what property of water has the definition: alot of energy is needed to raise 1kg of water by 1C
High specific heat capacity.
How does high specific heat capacity help organisms?
Prokaryotes and Eukaryotes-High specific heat capacity of water stabilises the habitat of aquatic organisms , temperature of water doesn’t fluctuate too much nor decrease too much.The water in the cyptosol of cells is at a constant temp=enzymes dont denature.
What property of water has the definition: lot of energy is needed to change the state of 1kg of water without raiding it temperature?
High latent heat of vaporisation.
How does high latent heat of vaporisation help organisms?
eukaryotes-This property allows them to use evaporative cooling, water moves faster when heated=more likely to become gas. It evaporates and removes heat and energy.
What property of water has the definition: water expands and becomes less dense below 4C?
prokaryotes and eukaryotes - In temperatures under 4C, the top layer of water freezes and insulates water underneath , this helps aquatic organisms since they can swim freely.
How does hydrogen bonding help organsims?
What property of water has the definition: a type of solvent that has a strong dipole moment due to the presence of polar bonds in its molecules.
a highly polar solvent
What does water dissolve as a highly polar solvent
it dissolves polar molecules and ionic compounds, it cant dissolve non polar molecules.
How does water being a highly polar solvent help eukaryotes?
Eukaryotes: Water serves as a main component of bodily fluids thus meaning it can transport things like nutrients in the body.CYTOSOL IN PRO N EU = MAINLY WATER SO THIS PROPERTY ENSURES SOLUTES CAN DISSOLVE IN THE CELL N EASILY BE TRANSPORTED
How does water being a highly polar solvent help prokaryotes?
Prokaryotes: Water serves as a main component of bodily fluids thus meaning water can help in the movement of substances across the cell membrane.
