T2.2 Water Flashcards
Chemical formula for water
H2O
Which type of bond is between the atoms in a water molecule?
Covalent bond
What is a hydrogen bond
Partly positive hydrogen atoms of one water molecule are attracted to the partially negative oxygen atms of another water molecule.
What contributes to the stability of water?
The large number of bonds between all the water molecules
1 water molecule can have hydrogen bonds with 4 more water molecules
Which molecules will water dissolve?
Other molecules that have polar covalent bonds and ionic compounds
D
How does sodium chloride get transported through blood?
When dissolved, NaCl forms Na+ ions and Cl- ions that is carried in the blood
Describe how sodium chloride is dissolved in water
- Water molecules pull the sodium and chloride ions apart, breaking the ionic bond
- This is because the positive hydrogen on water is pulled toward the negative chloride ions, and vice versa for the oxygen and sodium
How do amino acids get transported through blood?
- Amino acids have negative and positive charges.
- Because of this, they are soluble in water
- Solubility varies depending on R group
- All are soluble enough to be dissolved in blood plasma
How does glucose get transported through blood?
Glucose is polar and is freely soluble in water, thus dissolved and carried in blood plasma
How does oxygen get transported through blood?
this one is a little complicated
- nonpolar molecule
- Small size makes it so it is kinddaaa dissolved in water, but blood can only become so saturated with it and only in low concentrations
- Far too little to provide for aerobic cell respiration, so blood uses hemoglobin in red blood cells to provide binding sites for the oxygen
- Increases the capacity of the blood for oxygen transport
How do fat molecules get transported through blood?
- entirely nonpolar, larger than oxygen, thus insoluble in water
- Carried inside lipoprotein complexes
Lipoprotein complexes
- groups of molecules with a single layer of phosphlipid on the outside
- fats are carried inside.
- Also proteins in the monolayer of phospholipid, hence the name lipoprotein
How does cholesterol get transported through blood?
- hydrophobic
- transported with fats in lipoprotein complexes
- In the phospholipid monolayer
Cohesion
hydrogen bonding between water molecules makes water stick together
Surface tension
cohesion of water molecules along a surface
net effect: stickiness at its surface that causes water to behave as if its surface were covered with a stretch elastic membrane
water has a higher surface tension than most liquids
Adhesion
Ability of water molecules to stick to other (polar or charged) surfaces
How is adhesion useful in plants
Interaction with cohesion leads to capillary action, which pulls water to tree tops
Capillary action
interaction of cohesion and adhesion, allows water to go against gravity without energy use
in xylem of plants
High specific heat capacity
- Specific heat - quantity of heat absorbed needed to increase by 1 degree K
- strong hydrogen bonds restrict motion of water molecules
- increase in temperature required to break hydrogen bonds
- takes a lot of energy compared to other compounds
Evaportion
Molecule separates from other molecules in a liquid to become a vapor molecule
Real world application of high specific heat capacity
Provides for stable internal enviroments and habitats
Sunbathers can absorb a lot of heat without sending their body temperature soaring.
Latent heat
Heat needed for evaporation
High latent heat of vaporization
Water requires a high input of energy to break hydrogen bonds
Real world application of high latent heat
Sweating: use of water as a coolant, heat is taken from tissues of the skin to evaporate, cooling off the body.
High boiling point
Highest temp it can reach at it’s liquid state
Water boiling point is high, meaning it can be in a broad range of temperatures (0-100°C)
Real world application of high boiling point
Temperature range can be found in most habitats on Earth
Why does methane have a much lower melting/boiling point than water?
Methane is non-polar, thus hydrogen bonds do not form between methane molecules. They are more weakly held together, and little energy is need to force the molecules apart.
Can you draw 5 water molecules bonding???
you better
