Chp 3 Water and the fitness of the environment Flashcards Preview

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Flashcards in Chp 3 Water and the fitness of the environment Deck (18):
0

Explain the 5 ways which the polar nature of water molecules creates an environment suitable for life.

1)Cohesion and Adhesion of H2O
In H2O h-bonding occurs giving this liquid more stability than most liquids this is called cohesion. Adhesion is defined as the clinging of one substance to another. Adhesion of H2O by H-bonds helps the cell walls by countering the down pull of gravity. Cohesion = surface tension the measure of how hared it is to break the surface of the liquid.
2)H2O's specific heat / high heat vaporization / high melting point
H2O has the ability to stabilize temperature stems from its high specific heat. Specific heat is defined as the amount of heat tht must be absorbed or lost for 1g of tht substance to change its temperature by 1 degree celcius. H2O's specific heat is 1calorie per gram and degree celcius. Heat of vaporization is the quantity of heat a liquid must absorb for 1g of it to be converted to the gaseous state. 1g of H2O needs about 25degree C or about 580 calories of heat. Tht about doubles alcohol. makes water unique.
3) Ice as a protective blanket
First H2O is one of few substances tht are less dense as solids than liquids. Ice floats on liquid H2O. H-Bonding allows this to occur. ice is about 10% less dense than Liquid H2O. If ice did not float all lake, ponds rivers and oceans would freeze completely and make life impossible to live.
4)Water is the solvent of life
H2O is a wonderful solvent due to its H-bonding. This is great for our body because H2O can dissolve proteins, blood, sap of plants and liquids withing cells. Making it the solvent of life.

1

Define solution

Solution is a liquid tht is a completely homogeneous mixture of 2 or more substances.

2

Define Solvent

Solvent is the dissolving agent of a solution

3

Define Solute

Solute is the substance tht is dissolved

4

Explain Cohesion and Adhesion on its importance to polarity of H2O

Cohesion and Adhesion of H2O
In H2O h-bonding occurs giving this liquid more stability than most liquids this is called cohesion. Adhesion is defined as the clinging of one substance to another. Adhesion of H2O by H-bonds helps the cell walls by countering the down pull of gravity. Cohesion = surface tension the measure of how hared it is to break the surface of the liquid.

5

Explain why H2O specific heat and vaporization and melting point helps create an environment suitable for life.

H2O's specific heat / high heat vaporization
H2O has the ability to stabilize temperature stems from its high specific heat. Specific heat is defined as the amount of heat tht must be absorbed or lost for 1g of tht substance to change its temperature by 1 degree celcius. H2O's specific heat is 1calorie per gram and degree celcius. Heat of vaporization is the quantity of heat a liquid must absorb for 1g of it to be converted to the gaseous state. 1g of H2O needs about 25degree C or about 580 calories of heat. Tht about doubles alcohol. makes water unique. H2O with such a high melting point and wide range for boiling point it makes its most natural state on the earth as liquid water. We as humans are around 80% water and we need water to survive. Thus living in an environment where ice can easily be melted and water is naturally liquid here is perfect for our existence on this planet.

6

Why is ice as a protective blanket have a significant impact on why we can survive ice ages?

Ice as a protective blanket
First H2O is one of few substances tht are less dense as solids than liquids. Ice floats on liquid H2O. H-Bonding allows this to occur. ice is about 10% less dense than Liquid H2O. If ice did not float all lake, ponds rivers and oceans would freeze completely and make life impossible to live.

7

How is the solvent of life?

Water is the solvent of life
H2O is a wonderful solvent due to its H-bonding. This is great for our body because H2O can dissolve proteins, blood, sap of plants and liquids withing cells. Making it the solvent of life. It reaches out and affects everything about this planet to help it survive. Without this amazing attribute this planet would not exist.

8

How do salts dissolve in water.

First when the salt enters the water, water is attracted to each individual ion due to there separate charges. The O in H2O is attracted to the positively charged sodium cation. H is positively charge and is attracted to the Chloride anion. Water then surrounds each individual sodium and chloride ion, shielding them from one another. Water will then eventually dissolve the ions.

9

What is evaporation cooling and how does it moderate global temperature as well as our temperature.

When evaporation is occurring the liquid left behind is now cooler than before because the hottest molecules hav turned into gas. Evaporation controls human temperature by evaporating sweat from the skin dissipates body heat and helps prevent overheating. Evaporation cooling of water moderates global temperature by providing a mechanism tht prevents terrestrial organisms from overheating.

10

Define pH

pH is defined as the negative logarithm of hydrogen ion concentration. it tells u if a solution is basic, acidic or neutral.
acids < 7 nuetral < basic

11

Define acids

Acids are H+ donor that increase the H+ ion of a sulution.

12

Define Bases

Bases reduce the H+ ion in solution. H+ acceptor.
Other may reduce H+ ions inderectly by dissociating to form OH-

13

Define buffer

a buffer is a substance tht minimizes changes in H+ ions and OH- ions in a specific concentration .

14

Define Hydrophilic

Hydrophilic - Loves water . any substance that has affinity for water is hydrophilic.

15

Define Hydrophobic

Hydrophobic - Substances tht repel water such as nonionic and nonpolar. Otherwise cannot form H-bonds.

16

Define mol

The measurement of a substance in grams

17

Define molar solution

The # of moles of a solute per liter of solution.