Chemistry Quiz. (Polarity + Acids and Energy)

Chem 316 Quiz #5 Name

Due Dec. 15, 2016, 1:45 pm (13:45)

Special Instructions: For this quiz, allowed resources to use for completing this quiz can be the book

(or other books found in a library or bookstore), any of the PowerPoints or other materials posted on

the class cougar courses site, or from publicly available electronic resources such as google. All work

must be the student’s own work. Students may NOT discuss, help, or compare answers among

themselves or with anyone else (except Dr G) by any means (written, verbal, electronic, or other).

1. (3 points) The pH scale is generally considered as a scale from 1 to 14. State a value of pH considered to be:

a. acidic ____________

b. basic ____________

c. neutral ____________

2. (1 point) The acid in our stomach is used to break down food proteins and kill bacteria and has what value pH?

3. (1 point) Our blood pH is what value?

4. (1 point) A solution in which pH does not change very much when small amounts of acid or base are added to it, is called a ____________

5. (4 points) Give 4 acids that are found as ingredients in food. Note that this means they are added to the food, not present naturally.

6. (2 points) What is the major acid found in coffee?

7. (1 point) What is the typical pH of coffee?

8. (2 points) What is the reaction responsible for the browning of food that gives colors and flavors when foods are baked, roasted, or toasted?

9. (2 points) What is the major antioxidant found in cocoa?

10. (3 points) To what class of compounds does the antioxidant in the question 4 above belong, and how is it affected by the alkalization process?

11. (1 point) What is the typical solution used to alkalize cocoa?

12. (1 point) Why (for what purpose) is cocoa alkalized?

13. (2 points) What is the typical pH of cocoa powder, and then what is the pH after alkalization?

14. (3 points) The calorie (cal) is the standard energy unit listed on food nutrition labels. How many calories do we get from food containing:

1. One gram of fat ____________

2. One gram of sugar ____________

3. One gram of protein ____________

15. Use the reaction below to answer the questions that follow.

CH4 + O2  CO2 + H2O (g) + 802 kcal

a. (2 points) Is energy absorbed or released in this reaction?

b. (2 points) This reaction is which of the following?

a. Exothermic b. Endothermic c. Monothermic d. Geothermic

c. (2 points) If you are holding the jar containing this reaction, will your hands get cold, warm, or not change temperature?

d. (2 points) A hot pack when activated is an example of an exothermic reaction. Give another example of an exothermic reaction:

e. (2 points) A cold pack when activated is an example of an endothermic reaction. Give another example of an endothermic reaction:

16. (3 points) What is a catalyst?

Academic Integrity Statement: I confirm that the work shown here is my own work, and that I completed this

quiz according to the Special Instructions listed above.

Student’s signature here: