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You will write the background,purpose, and procedure is as follows: Part I
1.prepare an ice water bath by partially filling one of the 50 ml beakers from your labpaq with tap water and crushed ice set aside.
2.prepare a hot water bath by partially filling the second 50 ml beakers from your labpaq with very hot tap water. Set aside.
3.Using a 24 well plate add 5 drops of 2.0 M MgC12 magnesium chloride solution to wells C1 and C2. Add 10 drops to wells C3and C4.
4.Add 1 drop of phenolphthalein to wells C1,C2,C3 and C4. Stir with a clean toothpick.
5.Add 5 drops of 1.0M NaOH,sodium hydroxide solution to wells C1,C2,C3 and C4. Stir and record your observations.
6.Add 1 drop of 6.0 M HC1,hydrochloric acid solution to well C1. Stir and record your observations. Continue to add HCI drop by drop to well C1 until you see a color change. Record your observations.
7.Add 1 drop of 0.15 M Na2EDTA to well C2. Stir and record your observations. Continue to add Na2EDTA drop by drop to well C2 until you see a color change. Record your observations.
8. Use the marker pencil to label an empty pipet “C3″ solution, and slowly release the bulb to carefully suck up all the mixture from the well into the bulb.
9.you need to place the pipet bulb from step 8 into the hot water bath, but it will tend to float. To avoid this, securely attach the pipet stem to a spoon handle with a rubber band. Then place the pipet bulb in the water bath with the spoon handle outside of the beakers so as to not obstruct your observations.
10.Repeat steps 8 and 9 with a second pipet filled with the mixtures in the pipet’s changes, record your observations.
11.After about 10 minutes exchange the pipets in the baths.(put the pipet from the cold water into the hot water bath and vice versa)
12.Dispose of your solutions by pouring them down the drain with running water. Rinse your 24 well plate and dry it. Remove the marker pencil marks from the pipets and rinse them well, by sucking up distilled water and squeezing it out. They will be used in the next part, so dry pipets completely.
Part II
1. using a 24 well plate,add 5 drops of NaHSO4 sodium bisulfate solution to wells A1,A2 and A3. Add 10 drops to wells A4 and A5.
2.Add 1 drop of thymol blue indicator to each well. Stir with a clean toothpick and record your observations.
3.Add 1 drop of Na2SO4 sodium sulfate solution to well A1 and stir with a clean toothpick. Compare the color of well A1 with that of well A2. Record your results.
4. Repeat step3, drop by drop, until you see a color change. Record your observations.
5. Add a few crystals of solid NaHSO4 to well A3. Stir with a clean toothpick, wait awhile, and record your observations. Compare the color of well A3 with that of well A2. Record your observations.
6.repeat steps 5 until you see a color change. Record your observations.
7.Use the marker pencil to label an empty pipet”A4″. Then squeeze the pipet bulb, place it in A4 solution, and slowly release the bulb to cearefully suck up all the mixture into the bulb.
8. You need to place the pipet bulb from stpe 7 into the hot water bath, but it will tend to float. To avoid this securely attach the pipet stem to a spoon handle with a rubber band. Then place the pipet bulb in the water bath, with the spoon handle outside of the beakers so as to not obstruct your observations.
9.Make sure the water bath is as hot as possible. If the water bath is not very hot the expected color change may be difficult to see. Place the pipet bulb from step 8 into the hot water bath. Record the beginning temperature of the hot water.bath
9.repeat steps 7and 8 with a second pipet for the mixture from the well A5 place this pipet into the cold water bath.
10.Record the beginning temperature of the cold water bath.
11.when you observe changes in the mixtures in the pipet’s record your observations and the water bath temperatures.
12.compare the final solutions to that in well A2 and record your observations.
13.after about 10 minutes exchange the pipet’s in the bath’s (put the pipet from the cold water bath into the hot water bath and vice versa) record your observations
14.dispose of your solutions by pouring them down the drain with running water.
Questions:
In part I the reaction you observed was Mg(OH)2(s) Mg2+)(aq). Compare the colors you observed in the experiment and answer these questions
A. which way should the equilibrium shift when HCI is added? How do your results support your answer?
B. which way should the equilibrium shift when Na2EDTA is added? How do your results support your answer?
C. Is this reaction endothermic or exothermic? How do you know?
Part II
In part II the reaction you observed was HSO4-(aq)+H2O(I) H3O+(aq)+SO42- compare the colors you observed in the experiment and answer these questions
A.which way should the equilibrium shift when Na2SO4 is added? How do your results support your answer?
B. Which way should the equilibrium shift when NaHSO4 is added?How do your results support your answer?
C. Is this reaction endothermic or exothermic?
