Chapter 3: Water and Life

PH scale

________ is used to measure whether a solution is acidic or basic.

Blooms of plankton

________ are forming in the Arctic due to warmer temperatures, but species depending on arctic ice are suffering.

Hydrophilic

________: substance that has an affinity for water (has a slight charge to it)

Hydrophobic

________: substance that does not have an affinity for water (doesnt have a charge)

Temperature

________ does not depend on volume, while thermal energy does as it focus on the total kinetic energy, rather than just the average.

Cotton towel

________- made up giant cellulose molecules.

Calorie

________ (cal): the amount of heat required to raise the temperature of 1g of water by 1ºC.

Kilocalorie

________ (kcal): the amount of heat required to raise the temperature of 1 kg of water by 1ºC.

Solute

________: substance that is dissolved in a solution.

Ratio of ice

________ and to liquid water on earth is changing due to climate change, having different effects on wildlife.

Evaporation

________ (vaporization): transformation of a substance from liquid to gas.

why is the surface tension of water so high?

Water hydrogen bonds to itself, not the air around above, causing asymmetry, which is why surface tension is so high.

Hydration shell

________: a sphere of water molecules surrounding each ion when an ionic compound is dissolved in water.

Concentration of H+

________ and OH- are equal in pure water.

what holds atoms in water molecules together?

hydrogen bonds

enzymes

All ________ are proteins, but not all proteins are ________.

Adhesion

________: an attraction between substances.

what is the effect of adding acids or bases into a solution?

Adding acids and bases changes the concentrations of H+ and OH-

Molarity

________ (M): the number of moles of solute per liter of solution.

how does the high specific heat of water help sustain life?

The high specific heat of water minimizes temperature fluctuations to within limits that permit life

Amylase

________ needs neutral environment and pepsin needs an acidic environment.

why does an oxygen atom in a water molecule have a partial negative charge?

In a water molecule, the electrons of the polar covalent bonds spend more time near the oxygen than the hydrogen atoms

Solution

________: liquid that is a completely homogeneous mixture of substances.

Carbonic acid

________ is a good buffer of the body- helps keep body neutral.

Evaporative cooling

________: as a liquid evaporates, its remaining surface cools.

Cohesion

________: an attraction between the same substance.

nonionic polar molecules

Water can also dissolve compounds made of ________

Why is water a polar molecule?

the overall charge of water molecules is uneven due to the difference in electronegativity of the oxygen and hydrogen atoms in water

Buffers

________: substances that minimize changes in concentrations of H+ and OH- in a solution.

a true homogenous solution is one that has concentrations that are…

even throughout the entire liquid.

Surface tension

________: a measure of how difficult it is to break the surface of a liquid.

why does ice float in liquid water?

ice floats in liquid water because hydrogen bonds in ice are more "ordered, "making ice less dense than water - creates crystalline lattice structure

Specific heat

________: the amount of heat that is must be absorbed or lost by a substance for 1g of that substance to change its temperature by 1ºC.

which atom(s) can shift from one water molecule to another?

A hydrogen atom in a hydrogen bond between two water molecules can shift from one to the other.

in which physical state are the hydrogen bonds in water fragile?

in the physical state

hydrogen bonds

IN PLANTS: cohesion helps with the transport of water and nutrients against gravity because as the water vapour evaporates from the leaves, ________ cause water molecules leaving the leaf veins to tug on molecules further down, and transmits an upward pull through water- conducting cells all the way to the roots.

Acid

________: substance that increases the H+ concentration of a solution.

Temperature

________: the average kinetic energy of the molecules in a body of matter.

concentrations of H+

Changes in ________ and OH- can drastically affect the chemistry of a cell.

how does adhesion play a role in maintaining a flow of water that counters gravity in plants?

the adhesion of water by hydrogen bonds to cell walls helps to counter the downward pull of gravity

Why is water a versatile solvent

water is a versatile solvent due to its polarity.

adhesion

an attraction between substances

cohesion

an attraction between the same substance

how does cohesion helps with transport IN PLANTS?

cohesion helps with the transport of water and nutrients against gravity because as the water vapour evaporates from the leaves, hydrogen bonds cause water molecules leaving the leaf veins to tug on molecules further down, and transmits an upward pull through water-conducting cells all the way to the roots

surface tension

a measure of how difficult it is to break the surface of a liquid

what property of water makes it a good heat sink?

water can absorb or release a large amount of heat with only a slight change in its own temperature

kinetic energy

the energy of motion

thermal energy

the kinetic energy associated with random motion of atoms or molecules

temperature

the average kinetic energy of the molecules in a body of matter

heat

the transfer of thermal energy from one body of matter to another

calorie (cal)

the amount of heat required to raise the temperature of 1g of water by 1ºC

kilocalorie (kcal)

the amount of heat required to raise the temperature of 1 kg of water by 1ºC

joule (J)

another unit of energy

specific heat

the amount of heat that is must be absorbed or lost by a substance for 1g of that substance to change its temperature by 1ºC

evaporation (vaporization)

transformation of a substance from liquid to gas

heat of vaporization

the heat a liquid must absorb for 1g to be converted to gas

evaporative cooling

as a liquid evaporates, its remaining surface cools

solution

liquid that is a completely homogeneous mixture of substances

solvent

dissolving agent of a solution

solute

substance that is dissolved in a solution

aqueous solution

solution in which water is the solvent

hydration shell

a sphere of water molecules surrounding each ion when an ionic compound is dissolved in water

hydrophilic

substance that has an affinity for water (has a slight charge to it)

hydrophobic

substance that does not have an affinity for water (doesnt have a charge)

what is an example of a hydrophilic material that does not dissolve in water

cotton towel - made up giant cellulose molecules - absorbs the water without coming apart when in contact with it

what hydrophobic molecule related to oils is a major ingredient of cell membranes

parts of the phospholipid bilayer (hydrophilic head with hydrophobic tail)

molecular mass

the sum of all masses of all atoms in a molecule

molarity (M)

the number of moles of solute per liter of solution

concentration of H+ and OH

are equal in pure water

can changes in concentrations of H+ and OH- drastically effect the chemistry of a cell?

yes, because it changes the acidity

acid

substance that increases the H+ concentration of a solution

base

substance that reduces the H+ concentration of a solution (accepts H+ or forms OH-)

why is carbonic acid a good buffer of the body?

it helps keep body neutral — CO2+H2O can form carbonic acid or hydrogen carbonate (basic), these two neutralize each other

what is an example of a nonionic polar molecule that can dissolve in water?

sugar / glucose