lab two

Question 1

homeostasis

Answer 1

maintaining constant internal environment within cells

Question 2

constant factors

Answer 2

temperature, salt concentration, osmolarity, and pH

Question 3

humans and animals have what internal pH

Answer 3

7.2

Question 4

acidity

Answer 4

measure of hydrogen ion concentration in aqueous solution

Question 5

what does p in pH stand for

Answer 5

negative logarithm to the base 10

Question 6

H in pH

Answer 6

hydrogen ion concentration

Question 7

what is pH of water based on

Answer 7

dissociation constant

Question 8

amphoteric

Answer 8

can act as acid or base (water)

Question 9

product of hydrogen ion and hydroxide ion

Answer 9

1.0 x 10^-14

Question 10

buffers

Answer 10

solutions that resist changes in pH
- contain weak acid and its salt
- prevent rapid internal pH changes

Question 11

2 methods of determining pH

Answer 11

1. colorimetric methods
2. pH meters

Question 12

colorimetric

Answer 12

• litmus paper (different dyes extracted from lichen)
• turns red in acidic solutions
• blue in basic solutions
• thymol blue

Question 13

thymol blue

Answer 13

commonly used chemical that changes color over wide ranges of pH
- can use it to estimate pH of solution whose pH is unknown

Question 14

molarity

Answer 14

concentration of a solution
- number of moles of a substance or solute dissolved per liter of solution

Question 15

molarity formula

Answer 15

molarity = concentration/molar mass

Question 16

concentration

Answer 16

mass concentration of solution (density)

Question 17

molar mass

Answer 17

mass of 1 mole of solute

Question 18

concentration =

Answer 18

molarity x molar mass

Question 19

molar volume

Answer 19

volume that one mole of a substance takes up