Properties of Water
How much of the body is water molecules?
2/3
What is the optimal pH range for most life?
6.5 -8.2. This is neutral pH, not an acid or base.
What percentage of the body is made of water
70%
Capillary Action
A process powered by adhesion that causes water molecules to move upward through a narrow tubes.
What is the combined result of adhesion, cohesion, and surface tension?
Allows plants to transport water from their roots up through small tubes (stems) to their leaves.
Cohesion of water
Attraction between molecules of the same substance. Due to hydrogen bonding that contributes to the transport of water against gravity in plants. Hydrogen bonds between the oxygen of one water molecule and a hydrogen of another water molecule.
Why does ice float on water?
Because of cohesion, the space below the hydrogen bonds in water molecules increase when frozen.
What causes capillary action?
Capillary action is caused by adhesion.
What gives water a high surface tension?
Cohesion.
Where do most cellular events take place?
In water
List 5 properties of water
It is cohesive and adhesive It has a high specific heat It has a high heat of vaporization It is less dense as a solid than a liquid It is a good solvent
How do polar molecules act like magnets?
Opposite charges attract.
How do acids taste?
Sour.
How do acids feel?
Stings.
Adhesion
The linking together of like molecules, often by hydrogen bonds.
pH
The pH of a solution is defined the hydrogen ion concentration. It's a chemical process by which plants trap light energy to convert carbon dioxide and water into carbohydrates (food).
Cohesion
Water molecules stay close to each other as a result of hydrogen bonding. At any given moment, many of the molecules are linked by multiple hydrogen bonds. These linkages make water more structured than most other liquids
Adhesion of water
Water sticks to any surface that is polar or has exposed nitrogens or oxygens.
What color do pH pager turn when exposed to acids?
orange/red.
What is a use for acids?
As a preservative in foods.
How does cohesion support life on Earth?
Cohesion creates a layer of insulation below ice (water molecules) which protects organisms below it.
What surrounds a bodies' cells?
water.
What are the results of surface tension on water?
The surface of water holds up heavier materials than itself. Even insects can walk on water.
What fills you bodies' cells?
water
Polarity of water
water is a polar molecule meaning it has opposite charges on opposite ends. This causes hydrogen bonds to form causing water to stick together.
In the test tube activity with water and and an index card, what caused the water to stay in the test tube?
Cohesion causes the water molecules to stick together with such force that they defy gravity.
What happens to electrons when two hydrogen atoms combine with an oxygen atom?
Electrons are not equally shared.
What do unequal electrons surrounding hydrogen and water atoms create?
Positive and negative areas called polar molecules.
Strong Acid
pH of 1 - 3 hydrogen concentration.
Weak Acid
pH of 4 - 6 hydrogen concentration.
Surface Tension
A measure of how difficult it is to stretch or break the surface of a liquid. Water has a high surface tension because of the hydrogen bonding of surface molecules.
Acid
A substance that increases the hydrogen ion concentration of a solution. Has a pH of 0 - 6.9.
What does water transport throughout the body?
Nutrients and other things the body needs.
How are hydrogen bonds formed in water?
since water is covalent, oxygen hogs the electrons which makes it slightly negative, hydrogen do not see electrons as much which makes them slightly positive. negative oxygen is attracted to the positive hydrogen atoms which causes a hydrogen bond to form.
