Lab 4 Acids video PDF

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Acids, Bases, and pH questions from Bozeman Science Video lecture. Open the video in one screen and this document in another screen. As you watch the video, you can pause it to put an answer into the document. Once you have completed the document, save it on your computer and then submit it through the Canvas Submit-It link.

1. This shows myoglobin with optimum activity at a pH of 6. Where is this protein found and why is this important? ANSWER: The protein is found in the muscles. 2. What happens if the pH starts shifting either higher or lower? ANSWER: The protein will de-nature and the muscles won’t work. 3. To talk about pH, what molecule do you need to talk about first? ANSWER: Water

4. What bond exists between the H and the O and the other H and the O? ANSWER: A polar covalent bond exists. 5. Oxygen has what sort of relationship with electrons? ANSWER: Oxygen pulls electrons toward it.

6. So what does that mean when we say O is pulling the electrons towards it? ANSWER: It means there is a partial negative charge on the oxygen side and hydrogen will have a positive charge on the other side. 7. That results in what sort of a charge on the O side of the molecule and what sort of charge on the H side of the molecule?

8. This results in what sort of a bond between two different water molecules and how do the two molecules face each other? ANSWER: Hydrogen bond 9. How does this explain cohesion? ANSWER: The polarity of water and corresponding hydrogen bonds will line up and as one is being pulled, the other will go along (cohesion).

10. What else happens as a result of this ‘strong’ attraction between two water molecules? ANSWER: Hydrogen atoms can detach from the water and attach onto other water molecules. 11. What do you call the two resulting ions and what sort of a charge does each of them have? ANSWER: Hydronium (positive charge) and Hydroxide (negative charge).

12. What does pH stand for? ANSWER: It is thought to stand for the power of Hydrogen or the amount of hydrogen.

13. What is the chance of having hydronium in distilled water? ANSWER: Really, really rare. 1 in 10 million.

14. What does it mean when we say the pH is 7? ANSWER: The concentration of the hydrogen ion is going to be really, really small. A pH of 7 is considered neutral.

15. If we vary the concentration of H, we vary the pH. That results in solutions that fall into what two ranges? ANSWER: The acid range and the base range.

16. What happens if we add hydrochloric acid to water? ANSWER: It will dissociate and break down into hydrogen ions and chloride ions.

17. What does that do to the concentration of hydrogen atoms and how does that effect the resulting pH?

18. What happens when we a base like sodium hydroxide (lye) to water? ANSWER: It breaks apart into sodium ions and hydroxide ions.

19. How is that going to effect the pH? ANSWER: It will gobble up the hydrogen ion and make the pH more rare (pH of 12).

20. Where do you find acids and bases on the pH scale? ANSWER: Acids are found below pH 7 and bases are found above pH 7.

21. The thumb up represents what and the thumb down represents what? ANSWER: The thumbs up represents increase in the amount of hydrogen ions in a solution (pH will be lower). The thumbs down represents decrease in the amount of hydrogen ions in a solution (pH will be higher).

22. How are our oceans becoming acidified? ANSWER: An increase in carbon dioxide in the atmosphere, combining carbon dioxide and water/carbonic acid leads to oceans being increasingly acidified.

23. pH scale is a log scale. What does that mean? (Hint: a shift of one pH number, such as pH4 to pH3, is a shift of 10x. So a shift of pH5 to pH3 is a shift of 10x10= 100…which since the pH is dropping, it means pH3 is 100 times more acidic than pH5) ANSWER: By decreasing by a small amount in the pH, it will be increased quite a bit in the hydrogen ion....