Practical Lab #1 Chemistry of Biology

Question 1

pH Scale

Answer 1

Closer to 1=stronger acidity
Closer to 14= stronger base
7=Neutral

Question 2

Acids have an increase in……

Answer 2

H+ ions

Question 3

Bases have an increase in……

Answer 3

OH- ions

Question 4

Whats is a Buffer?

Answer 4

A solution that resists changes in pH when acid or alkali is added to it.

Question 5

What indicators are used to determine pH range?

Answer 5

Bromothymol Blue (BTB) and Phenol Red (PR)

Question 6

Positive BTB

Answer 6

Color changes from blue to yellow

Question 7

Positive PR

Answer 7

Color changes from red to yellow

Question 8

How are various antacids tested for their buffering capacities?

Answer 8

1. Measure out 10ml of de-ionized water into two different beakers marked BTB and PR
2. Add 3 drops of BTB to one beaker and 3 drops of PR to the other
3. Add 3-5 drops of the first solution into both beakers and record any color change. No color change= Base Color Change= Acid
4. Test the pH scale with pH testing strips