LAB 02: pH, buffers & water properties
In addition to ALL QUESTIONS present in your lab manual in pages 21-23, review the following…
All the following questions can be answered out of what you did in the lab during that activity!
- Know the pH scale and what it means regarding the amount of H+ (acidity) or OH- (alkalinity)
- Let’s imagine substance A has pH 6 and substance B has pH 3. How many times more acidic is substance A compared to substance B?
- Why is the water molecule said to be “polar” and how is that connected with the “hydrogen bonds”?
- How does a buffer solution work? What solution was used to show this? Which other natural fluid is mentioned as having buffer properties?
- Explainthe properties ”heat of vaporization”, “specific heat”, “cohesion”, and “surface tension”. The water’s polarity and the ability to make hydrogen bonds are responsible for all these properties in water.
- Describe the way you did the experiment for specific heat and explain the results you got in the form of a graph
- Which had a higher specific heat, water or alcohol?
- Explain the difference between a blind and double blind experiment. Which one did you actually do in the lab and for what experiment?
- Which had a higher heat of vaporization, water or alcohol?
- Describe the way you did the experiment for capillary action heat and explain the results
- For the previous, you had 3 different experiments. You measured in all three the capillary action by seeing how much the liquid would “climb” in the tube..
- Capillary action was then your dependent, Y variable that you measured
- Which were your independent X variables in each one of these experiments? In other words how were the two set ups different in each of the three cases (Look at the table on page 18)
- Which had a higher capillary action water or alcohol?
Instructor: Jose Bava, Ph.D