Lab+3+Water

Exercise 1: 1.What IS pH? pH stands for potential of hydrogen. A pH test measures whether something is an acid or an alkaline by testing how much hydrogen is in the substance.

 2. What makes hydrogen chemically active?

 3. What does it mean when something is acid? When something is acid, that means that it reads between a 1 and a 6 on the pH scale.

4. What does it mean when something is basic? When something is basic, that means it reads between a 8 and a 14 on the pH scale.

5. How much more acidic is something that is pH 3 than pH 4? A pH of 4 is 10 times more acidic than a pH of 3.

6. How does the acidity or alkalinity of food affect human taste buds? Foods which have more of an alkaline taste, taste bitter, whereas acids taste sour.

a. Acid-Base Balance in the Body The lungs and kidneys help balance the body's pH levels. Carbon dioxide is acidic, so in breathing, a certain amount of acidity is released into the blood stream. The faster a person breathes, the less acidic their blood becomes, because their body is regulating the pH levels. Carbon dioxide leaves the body upon exhalation.

b. Carbonic Acid-Bicarbonate Buffering The bicarbonate buffer essentially keep the body's pH levels in check. Upon exhalation, the body rids itself of CO2.  When there is too much hydrogen in the body, the hydrogen begins to react with the bicarbonate ions. Hydrogen and bicarbonate create carbonic acid which fluctuates back into the body keeping the body's pH levels at a perfect homeostasis.

Results of using Red cabbage as a colorimetric indicator Exercise 2:
 * Chemical added || number of drops || color || ph using paper ||
 * control || 0 || - || 7 ||
 * vinegar || 10 || pink || 9 ||
 * baking soda || 15 || light yellow (opaque) || 3 ||

<span style="font-family: Arial,Helvetica; font-size: medium; line-height: normal;">Effect of buffer on pH change in reaction to vinegar addition


 * Chemical added || Number of Drops || color || ph before vinegar || ph after vinegar ||
 * B || 17 || very light violet || 9 || 5 ||
 * C || 0 || - || 3 || - ||