Lab 4, Part 3 - Acids, Bases, and PH

Acids, Base Bases, s, and pH question questionss from Bo Bozeman zeman 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? It is found in your muscles and it is essential for our muscles to function correctly. 2. What happens if the pH starts shifting either higher or lower? The proteins are going to denature, and our muscles aren’t going to work. 3. To talk about pH, what molecule do you need to talk about first? We need to talk about water first. 4. What bond exists between the H and the O and the other H and the O? There is a covalent bond. 5. Oxygen has what sort of relationship with electrons? Oxygen is greedy and pulls the electrons toward itself. 6. So what does that mean when we say O is pulling the electrons towards it? There is a polar covalent bond and sharing of electrons, 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? There is a partial negative charge on the O side, and a positive charge on the H side. 8. This results in what sort of a bond between two different water molecules and how do the two molecules face each other? It results in a hydrogen bond because the negative O side of one molecule attracts to the positive H side of another. 9. How does this explain cohesion? This pulls the water molecules together, which is why there is cohesion. 10. What else happens as a result of this ‘strong’ attraction between two water molecules? The hydrogen atom will become detached from the water and it will become attached onto the other water molecule. 11. What do you call the two resulting ions and what sort of a charge does each of them have? The two resulting ions are hydronium (which has a positive charge) and hydroxide (which has a negative charge). 12. What does pH stand for? It stands for the power of hydrogen. 13. What is the chance of having hydronium in distilled water? Very rare – a 1 in 10,000,000 chance. 14. What does it mean when we say the pH is 7? It means that the concentration of the hydrogen is very small. 15. If we vary the concentration of H, we vary the pH. That results in solutions that fall into what two ranges? It falls in the ranges of bases or acids. 16. What happens if we add hydrochloric acid to water? It is going to disassociate 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? It can increase the odds from 1 in 10,000,000 to 1 in 100, and it could have a pH of 2. 18. What happens when we a base like sodium hydroxide (lye) to water? It is going to break apart into sodium and hydroxide ions. 19. How is that going to effect the pH? It is going to create a pH of 12. 20. Where do you find acids and bases on the pH scale? Anything above a pH of 7 is a base, and anything below 7 is an acid. 21. The thumb up represents what and the thumb down represents what? The thumbs up represents increasing the amount of hydrogen ions in a solution, and the thumbs down represents the pH lowering. 22. How are our oceans becoming acidified? As the amount of carbon dioxide in the atmosphere increases, that carbon dioxide combines with water and creates carbonic acid in the ocean. 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) By decreasing a small amount in the pH scale, it increases a lot in the hydrogen ions.