Chapter 2 : pH and water Flashcards
Polar molecules ____ in water
dissolve
What can water dissolve ?
Polar and charged molecules
Solution definition
Two substances mixed together
Solute definition
Substance to be dissolved (sugar)
Solvent definition
The one doing the dissolving (water)
In salt water , Salt is the ____?
Solute
( smaller amount)
Cohesion definition
Similar things attract together
(water molecules cling together)
Cohesion with water does what?
Gives water capacity to resist breaking under tension
Why is Cohesion important?
Cohesion in water allows blood to move easier in blood vessels
(also moves water in plants)
Acid definition
Substance that donates hydrogen ions when in solution
(gives up H+)
Base definition
Substance that accepts hydrogen ions when in solution
(accepts H+)
Inverse definition
Higher the pH the lower the concentration of H+
Logarithmic definition
Increase in pH represents 10x decrease in H+ concentration
Ph scale :
Below 7 is what ?
Acidic
Ph scale :
At 7 is what ?
Neutral
Ph scale :
Above 7 is what ?
Basic
The higher the pH a solution has , the higher the H+ concentration?
False or True ?
False
Is a pH of 8 acidic or basic ?
Basic
(slightly basic to be exact)
The H+ concentration of a solution with a pH of 4 is ____ higher/lower than a solution of 2
100x Lower
Biological Fluids definition
Have buffers to keep pH stable
Buffer definition
Prevent change in pH
Remove extra H+ from solutions when the concentration of H+ increase
Add H+ when the concentration of H+ decreases
Why do body fluids have buffers?
To maintain stable internal enviornment
Draw a water molecule and draw hydrogen bonding between water molecules
https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.usgs.gov%2Fmedia%2Fimages%2Fstrong-polar-bond-between-water-molecules-creates-water-cohesion&psig=AOvVaw2uPGBIu9eP1IRvtSHbao6R&ust=1674884983708000&source=images&cd=vfe&ved=0CBAQjhxqFwoTCKjN6viG5_wCFQAAAAAdAAAAABAE
What are the four properties of water?
Have excellent polar solvent
Have cohesion
Have high heat capacity
Have high heat of vaporization
What is important about water having an excellent polar solvent?
Water is polar and forms hydrogen bonds. Acting as a solvent for polar molecules
What is important about water having cohesion?
Cohesion of water allows blood to move easier in the blood vessels
What is important about water having high heat capacity?
Water in our bodies helps keep us at a constant temperature
What is important about water having high heat of vaporization?
When we seat the body uses its heat to vaporize the water- cooling us off
What is the pH scale?
What are the scales ?
The higher the pH , the lower the concentration of H+
Each point increase in pH represents a 10 fold decrease in H+ concentration
Which of the following picture best represents two water molecules hydrogen bonding together?
C:\Users\Minelly\Downloads\h bonds.PNG
A
B
C
D
B
Which property of water is responsible for living organisms staying at an even temperature due to the fact that it takes a great deal of energy to raise the temperature of water?
Water is an excellent polar solvent
High heat capacity
High heat of vaporization
Water is cohesive
High heat capacity
In salt water, which is considered the solute?
Salt
Substances that donate hydrogen ions when in solution are?
Acids
The H+ concentration of a solution with a pH of 8 is ____ higher/lower than a solution of 7.
100 X higher
1 X higher
10 X lower
1 X lower
10 X higher
100 X lower
10x lower
A solution with a pH of 4 would be considered acidic or basic?
Acidic
A ________ is a substance that prevents solutions from changing the pH by either accepting or releasing hydrogen ions.
solutes
acids
bases
buffers
isomers
Buffers
