Chapter 3 water and life

More efficient for a fluid with a lower specific heat

(If organisms consisted of alcohol instead of water) In order for living things to inhabit a wide range of environments temperature revaluation would need to be ____

The effects would be drastically worse because the loss of the polar nature of water would greatly reduce its specific heat and its ability to moderate temperature

If water were NOT a polar molecule, how would the effects of global warming differ from those currently observed or predicted to occur in the future?

The oxygen atom in on water molecule and a hydrogen atom in another water molecule

In a group of water molecules hydrogen bonds form between which of the following

evaporative cooling

based on water's high heat of vaporization. The evaporative loss of the most energetic water molecules cools a surface

kinetic energy

energy of motion

Cohesion

Hydrogen bonding keeps water molecules close to each other giving water

polar covalent bond

A covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive.

Solution

A homogeneous mixture of two or more substances

Surface tension

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

100 times more H+

A solution at pH 6 contains ____ than the same amount of a solution at pH8

Solute

A substance that is dissolved in a solution.

Lower the hydrogen ion ceo vent ration and increase the pH

Adding a base tends to _________ of a solution

Increase the hydrogen ion concentration and lower the pH

Adding acid tends to __________ of a solution.

Adhesion

An attraction between molecules of different substances

A slight negative charge on the oxygen atom and a slight positive charge on the hydrogen atom

Because oxygen is more electronegative than hydrogen, electrons of the polar bond spend more time closer to the oxygen atom resulting in

Waste products produced by cell metabolism can be easily removed, a variety of nutrient molecules is readily available as dissolved solutes, the temperature of living things tends to change relatively slowly

Cells are surrounded by water, with which they are mostly filled. Which of the following occurs as a result?

Buffer

Consists of an acid base pair that combines reversible with hydrogen ions allowing it to resist pH changes

Bases

Donate OH- ions or accept H+ ions in aqueous solutions

ocean acidification

Due to the increased levels of CO2

Hydrogen bond

Forms when a partially negatively charged region on the oxygen of one water molecule is attracted to the partially positively charged hydrogen of a nearby water molecule

Ten times as much

Grapefruit juice is approximately pH 3, and tomato juice is approximately pH 4. A glass of grapefruit juice contains _____ H+ as a glass of tomato juice.

thermal energy

Heat energy

Specific heat

Heat is absorbed when hydrogen bonds break and is released when hydrogen bonds forms

Because it's polar waters negatively charged oxygen atoms and positively charged hydrogen atoms are attracted to positively and negatively charged ions and molecules

How does the polarity of water contribute to its ability to dissolve so many substances

Hydrophobic

Non polar molecules that cluster away from water molecules

Hydrophilic

Substances that do not have an affinity for water

Hydrophobic

Substances that have an affinity for water

heat of vaporization

Sweating has a cooling effect because of waters high

both caused by water's partial charges

The ability of water molecules to form hydrogen bonds with other water molecules and water's ability to dissolve substances that have charges or partial charges are __________

increases the hydrogen ion concentration in the oceans but decreased the carbonate ion concentration and threatens the livability of the oceans for the organisms that produce calcium carbonate shells

The absorption of human generated CO2 by the oceans

Specific heat

The amount of energy required to raise the temperature of 1 gram of a substance by 1 degree celcius

The heat vaporization of that substance

The amount of heat required to convert 1 g of any substance from the liquid to the gaseous state is defined as __________.

pH

The concentration of H+ is expressed as

Molecular mass in daltons

The mass of a mole of a substance in grams is the same as the

The unequal sharing of electrons between the hydrogen and the oxygen atoms of a water molecule

The partial charges on a water molecule occur because of __________.

Cohesion

The phenomenon responsible for maintaining the upward movement of water through vessels in a tree is

Specific heat

The reason that costal climates are more moderate than inland climates primarily waters high

molecular mass

The sum of the masses of all the atoms in a molecule

is called cohesion, acts to moderate temperature, provides the surface tension that allows small animals to move across a water surface, and helps to keep water moving through the vessels in a tree trunk

The tendency of water molecules to stay close to each other as a result of hydrogen bonding __________.

A higher boiling point

Water has __________ than other liquids such as ethanol , reflecting its capacity to absorb large amounts of heat.

Specific heat

Water has a high

polar molecule

Water is a

The atoms in the molecule have partial charges as a result of unequal sharing electrons in a covalent bond

Water is a polar molecule. What does that mean

Polar

Water is a versatile solvent because water molecules are _______

Solvent

Water is an unusually versatile _______ because its polar molecules are attracted to ions and polar substances that can form hydrogen bonds

1. Cohesive behavior 2. Ability to moderate temperature 3. Expansion upon freezing 4. Versatility as a solvent

What are the 4 emergent properties of water?

All properties related to hydrogen bonding

What do cohesion, surface tension and adhesion have in common with reference to water

Condensing 5 g of steam to liquid water

Which action would involve the greatest transfer of heat?

In order to perform their function of separating the aqueous solutions outside of cells from the aqueous solutions inside of cells, cell membranes cannot be soluble in water.

Why are cell membranes composed primarily of hydrophobic molecules?

because it is less dense than water

Why does ice float?

More carbon dioxide causes an increase in carbonic acid which leads to a decrease in concentration of carbonate ion

Why is there an increasing amount of carbon dioxide behind taken up by the oceans a cause for concern

Surface tension

You can fill a glass of water to just slightly above the rim without it spilling over. What property of water best explains the phenomenon

An acid

a compound that donates hydrogen ions to a solution

Buffer

a substance that minimizes changes in the concentrations of H+ and OH- in a solution is a

Mole

certain number of molecules of a substance

Temperature

represents the average kinetic energy of the particles that make up a material

Acids

donate H+ in aqueous solutions

polar molecule

molecule with an unequal distribution of charge, resulting in the molecule having a positive end and a negative end

Adhesion

the clinging of one substance to another substance

Solvent

the dissolving agent of a solution

molairty

the number of moles of solute per liter of solution. Used as a measure of solute concentration in solutions

Cohesion

the sticking together of particles of the same substance Often by hydrogen bonds

ocean acidification

when CO2 dissolves in seawater, it reacts with water to form carbonic acid, which lowers ocean pH