water and pH

What range do bases

7.1-14

what does it mean when we say that water is polar

a substance with molecules with oppositely charged ends ( positive and negative)

9. Lemonade is a mixture of lemonade powder and water: a. What is the solute in this solution? b. What is the solvent?

a.Lemonade powder b. water

Capillary action is actually the result of 2 of the other characteristics of water

adhesion and cohesion

adhesion

water attracting to other surfaces

high specific heat

water can absorbs a lot of heat before its tempature changes.

ice is less dense than water WHY

water expands in the solid state because all of the atoms are bonded to one another with hydrogen bonds.

cohesion

water is attracted to itself

capillary action

water's adhesive and cohesive properties allow it to be drawn upwards against the force of gravity. This allows water to flow up inside plant stems.

8. What does it mean when we say "like dissolves like." Give an example of this.

water's polarity allows the molecules to dissolve polar/charged substances, and non-polar molecules dissolve non-polar substances. Salt dissolving in water is an example of charged particles being dissolved by water.

versatile solvent

water's polarity allows the molecules to surround and break apart the particles in polar/charged substances and dissolves them

what does non-polar mean and give and example

no charge EX: oil

10. What is the range of the pH scale

0-14

What range do acids fall in

0-6.9

3. Why do hydrogen bonds form? Draw a diagram of a hydrogen bond.

A Hydrogen bond is a weak attraction between the partially positive H atom one molecule and the partially negative oxygen atom on another.

16. What are buffers

Buffers are substances which remove excess H+, Hydrogen ions and OH-, Hydroxide ions from solutions, helping to maintain pH at a certain level.

Explain 2 different reasons why pH is important to living things

Low pH can destroy enzymes and cells. pH influences the structure and the function of many enzymes (protein catalysts) in living systems

6. How is the density of ice compared to liquid water unique (different from other liquids/solids)? Why is the density of ice important to living things?

Most other substances are most dense as a solid. The significance of ice being less dense is because it allows ice to float on bodies of water and form an insulating barrier, rather than the whole lake/pond etc. to freeze solid

surface tension

The cohesion of water and the fact that it is more attracted to itself than to the air it leads to the formation of an elastic type of barrier at the surface. Some insects live on the surface of the water using this property.

Why is it important that water is such a versatile solvent?

This is important because substances must be dissolved in order for chemical reactions to take place