Bio 189 Unit 1 (Lecture 5)

10. The insides of your intestines has a pH of 8. Is the insides of your intestines acidic or basic? What is the hydrogen ion concentration ([H+]) and the hydroxide ion concentration ([OH])?

Basic Concentration of H+= 1x10^-8 Concentration of OH= 1x10^-6

5. A solution has [OH-] = 1x10-2 M. What is the pH of the solution? Is the solution acidic or basic?

*[H+] x [OH-]= 1x10^-14* (1x10^-14)-(1x10^-2)= [H+]= 1x10^-12 pH=-log[1x10^-12) pH= -(-12) pH=12 (BASIC)

6. Which is more acidic: A solution with a pH of 8 or a solution with a pH of 5?

A solution of 5

1. What is an acid? How does adding an acid change the [H+], [OH-] and pH of a solution?

Acid helps increase hydrogen ion [H+] in solution. Adding an acid can change the: -[H+]: more/increasing -[OH-]: few/decrease -pH of a solution would be LESS than 7 on the scale.

11. Your stomach produces gastric juices to help digest the food that you eat. Gastric juice has a pH of 2. Is gastric juice acidic or basic? What is the [H+] and the [OH]?

Acidic [H+]=1x10^-2 [OH]= 1x10^-12

2. What is a base? How does adding a base change the [H+], [OH-] and pH of a solution?

Base helps decrease hydrogen ion [H+] in solution. Adding a base can change the: -[H+]: few/decrease -[OH-]: more/increasing -pH of a solution would be MORE than 7 on the scale.

8. What is a buffer? What is the role of buffers in blood?

Buffer prevent changes in pH. Will act as a base or acid in order to prevent any changes of the [H+]. Buffer can help regulate pH in our blood .

9. If a solution has a pH of 10, what is the concentration of H+ ions? OH ions?

Concentration of H+= 1x10^-10 Concentration of OH= 1x10^-4

7. What happens when an acid is combined with base?

Neutralization occurs and will mix acid and base to give off salt and water.

14. You have two solutions, one solution is at pH 10 and the other solution is at pH 2. Which solution is more acidic? How much more H+ concentration does the more acidic solution have compared to the other?

pH 10 -> [H+]= 1x10^-10 pH 2 -> [H+]= 1x10^-2 (10-2=8) pH 2 is more acidic by 8 (or 1x10^-8).

15. You have two solutions, one solution is at pH 3 and the other solution is at pH 9. Which solution is more basic? How much more OH concentration does the more basic solution have compared to the other?

pH 3 -> OH= 1x10^-11 pH 9 -> OH= 1x10^-5 (11-5=6) pH 9 is more basic with more OH concentration by 6.

3. What is pH? How is it determined, and what does it describe?

pH is the measure of [H+] of solution. pH can be determine by the equation, pH= -log[H+]. pH helps describe the measure of concentration of H+.

13. A solution of bleach used for cleaning bathroom floors has a concentration of 1 x 10-12 M of H+. What is the pH of this solution? Is this solution acidic or basic?

pH=-log(1x10^-12) pH=-(-12) pH= 12 BASIC

12. A sugary feel-good drink mixed with lemon juice, orange juice, and few other interesting things has a concentration of 1 x 10-4 M of H+. What is the pH of this solution? Is this solution acidic or basic?

pH=-log(1x10^-4) pH=-(-4) pH= 4 ACIDIC

4. A solution has [H+] = 1x10-2 M. What is the pH of the solution? Is the solution acidic or basic?

pH=-log[1x10^-2] pH= -(-2) pH= 2 (ACIDIC)