water Flashcards
What partial charge does oxygen have and what does that mean
Electronegative (electrons are closer to the oxygen so it carried a negative charge)
Does water (a polar molecule) dissolve polar or non polar molecules?
Polar (has a partial charge)
Why is water liquid at room temperature 0-100
Because there isn’t enough energy to overcome the many hydrogen bonds, but enough that they keep breaking and reforming and not in a fixed giant lattice structure that ice is in
Are hydrogen bonds strong or weak
Weak but as there are many of them, large amounts of energy is needed to break them
Cohesion is when water molecules attract to
Each other
Adhesion is when water molecules attach to
Other molecules
Cohesion and adhesion assist in
Transpiration through the xylem
Why is water thermostable habitat for a biodiverse aquatic life?
It has high specific heat capacity - Large amount of thermal energy is needed to change the temperature by breaking hydrogen bonds
How is water used for thermoregulation in the body?
It has high latent heat of vaporisation - large amounts of thermal energy is needed to break hydrogen bonds and change state so heat energy is used up when evaporating sweat which cools down the skins surface
Why is water a good transport medium?
Water is a universal solvent - polar molecules can be dissolved because the charges are attracted to the opposite charged region of the water molecules
How does ice float and what is the benefit of it?
Water is less dense in its solid state as ice as hydrogen bonds are fixed - Creating a habitat for polar bears and an insulating layer underneath allowing a thermostable environment for fish that polar bears can eat
What allows water to become a habitat for water Bowman
It has high surface tension
What uses does water have due to its incompressibility?
-It is the hydrostatic skeleton of a jellyfish which loses its shape out of water
-It holds the structure of the eyes
-It keeps plants turgid
-It Creates buoyancy for big animals like the blue whales so they float
What is the benefit of water being transparent?
It allows light to be reflected to the retina for sight
Light can be reflected to the bottom of the ocean for underwater photosynthesis
Water has low viscosity (resistance to flow) so it is a great transport medium. why is this good?
It’s a fast transfer of nutrients in the bloodstream
What does delta mean and when is it used
It means partial and it used to describe the partially negatively charged oxygen and the partially positively charged hydrogen in water
What causes adhesion and cohesion?
The hydrogen bonds between water molecules
What is a hydrogen bond?
A weak bond between a slightly positively charged hydrogen atom in one molecule and a slightly negatively charged atom in another molecule
what is and Why does water have high specific heat capacity?
specific heat capacity is the energy required to raise 1kg of the material by 1°C
When water is heated, a lot of energy is absorbed by the hydrogen bonds between water molecules so it takes a lot of energy to increase the temperature and break hydrogen many bonds
Why does the polarity of water make it a good transport medium?
It makes water very cohesive and adhesive and a good solvent
Why is the structure of ice like this
Because the water molecules are being held further apart by fixed hydrogen bonds and they have formed a lattice shape
How is the formation of ice beneficial for organisms living in the water?
In cold temperatures, ice forms On top of the water, creating an insulating layer. meaning the organisms living in the water below don’t freeze and can survive
Describe how an Mg2+ ions dissolve in water
The slightly negatively charged Oxygen from the water molecules are attracted to the positive ion and will surround it
Why do kangaroos lick saliva onto their forearms in hot weather?
water has high latent heat of evaporation. Meaning A lot of thermal energy is used and removed from the kangaroos body when the water from the saliva evaporates off the kangaroos body, this reduces the kangaroo body temperature
Why do trees stay cool even in hot weather?
Trees have a high water content, Water has high specific heat capacity meaning it takes a lot of energy to break the hydrogen bonds and heat up which means it doesn’t heat up as quickly as air
How does water flow up a tree to leaves
Polar water molecules form hydrogen bonds between them making them cohesive And between other molecules, i.e. cells of the xylem which allows them to travel up the xylem
