Flashcards in Properties Of Water Deck (13):
What feature allows water to dissolve many substances?
Water molecules are polar due to the very electronegative oxygen atom having more control over the electron pair and an overall asymmetrical shape. It's polar nature and hydrogen bond allows it to dissolve other substances.
What feature gives water it's high MP and BP, high latent heat values and high specific heat capacity?
Water's strong hydrogen bonds mean that large amounts of energy are needed to be absorbed before the bond breaks between the water molecules.
What feature allows water to expand upon freezing?
Water expands upon freezing because each water molecule forms a hydrogen bond with four other water molecules when in solid form. This is to allow for better hydrogen bonding.
What are the properties of the group 16 hydrides? Why is water an exception?
- mp and bp increase down the group due to increase in dispersion forces
- water has significantly higher mp and bp due to being able to form 4 hydrogen bonds per molecule. A large amount of energy is needed to break these bonds.
What is specific heat capacity?
A measure of the amount of energy needed to increase the temperature of 1g of a substance by 1•c
What is the formula for specific heat capacity?
q = C x m x ^t
q - heat energy in j
C - SPC in Jg-1c-1
m - mass in grams
t- change in temp
What benefits does waters high SPC bring to living organisms?
- water is resistant to sudden temperature change, so ocean temps don't fluctuate too much.
- aquatic organisms do not need to survive sudden changes in surrounding water temp
What is latent heat?
The amount of nervy required to change to phase of a substance.
Fusion- solid to liquid
Evaporation- liquid to gas
What is the equation for latent heat?
q = n x L
q - heat energy
n - amount of substance in mole m/MR
L - latent heat value
What does solubility refer to?
The ability of a solvent to dissolve requires an adequate force of attraction between the solute and the solvent particles.
What is the biological importance of water dissolving many substances?
- transport of nutrients in organisms
Why do coastal regions not experience extreme temperatures like inland regions do?
Due to its high heat capacity, water absorbs a lot of heat energy, resulting in cooling of the surrounding land and air during the heat of the day. It also loses it slowly, resulting in warming during the cool night. As a result, the temperature tends to be more moderate.