1SCS #9-27, 33, 35

9. 20% of 55 =11 grams (mass of the sugar) --> 55-11= 44 grams (mass of the water)

10. 0.0015 x 1,000,000 = 1500 ppm

11. Water molecules are polar due to electrically negative oxygen at the end of the water molecule and positive hydrogen at the end. This is because oxygen is more electronegative than hydrogen. Electrons are partially pulled away from the two hydrogen atoms, and toward the oxygen atom.

12.

13. A. O-
      B. H+

14. Heavy metals are called "heavy" because their atoms have greater masses than those of essential metallic elements.

15. Three symptoms of heavy metal poisoning are damage to the nervous system, brain, kidneys. More symptoms may include liver damage and death.

16. Sources of human exposure to lead may be from some homes build before 1978. Since some of these homes may have not been repainted, the flaking of old lead paint is a source of human exposure to lead poisoning. Sources of human exposure to mercury may be through fish with high exposures of this, and a high intake of fish.

17. Hydroxide ions are found in many bases.

18. Hydrogen atoms are found in most acids.

19. A. Basic
      B. Basic
      C. Acidic
      D. Neutral

20. A. Soft drinks
      B. Black coffee
      C. Milk of magnesia

21. Two times more acidic.

22. Inappropriate pH levels on aquatic organisms cause alkaline solutions are able to dissolve organic materials, including skin and scales. Also, fish-egg development is impaired. This harms the fish to produce.

23. Nonpolar molecules do not dissolve well in polar solvents. On the other hand, polar substances dissolve in polar solvents, while nonpolar substances dissolve in nonpolar solvents. This is known as the "like dissolves like".

24. I would select a lamp oil to dissolve a nonpolar molecular substance because nonpolar molecules are known to not dissolve well in ethanol or water.

25. Table salt (NaCl) will dissolve in water but not in cooking oil because NaCl is a polar substance, therefore it cannot dissolve in oil.

26. The phrase "like dissolves like" means that polar substances dissolve in polar solvents, while nonpolar substances dissolve in nonpolar solvents. Basically, polar with polar, nonpolar with nonpolar.

27. You cannot satisfactorily clean greasy dishes with just plain water because water is polar, and oil (grease) is nonpolar, therefore they do not mix and cannot cancel each other out in a way.

33. Milk of magnesia and oven cleaner contain bases may be found in these cleaners. Using these cleaners is more effective than washing with water because these cleaners are more efficient and get rid of more of the grease with substances that mix with oil better than water.

35. Due to flourine having a higher electron density than hydrogen, I think that hydrogen would have a partial positive charge.

Explain how the solubility curve lab works.

The solubility curve lab works by adding succinic acid at different temperatures and measuring its solubility.

Explain how to do solution concentration problems. What is the tricky part?

The tricky part of these problems are calculating the percent of mass. It can also be tricky for some to find the mass of the solute and to divide it by the mass of the solution. You then multiply this by 100. There are other ways too, but this is the way that I prefer.

C.5 #1-3

1. Since you are cooling the solution, it will become supersaturated. 

2. 20 grams of water must evaporate at this temperature to create a saturated solution. 

3. The KCl is more spread out in 3b due to adding more water.

 

Explain your way of solving math word problems when answering solubility questions.

In order for me to solve math word problems when answering solubility questions, I have to understand the chart given to me. I have to be focused and have a good understanding of the question as well of the chart.

C.2 questions #1-3 p.56

1. a) 105 grams

    b) 47 grams

2. a) 20 grams

    b) 20 grams 

3. a) 90 grams

    b) 200 grams of water would have to be added

1SCS #1-8 p.82 

1. Three teaspoons of sugar will completely dissolve in a serving of hot tea, but will not dissolve in an equally sized serving of iced tea because because of the difference in mixtures. The hot water has a bigger gap for the molecules, allowing more space for the sugar molecules to fit in between. 

2. The maximum mass of potassium chloride that will dissolve in 100.0 g water at 70 degrees c is 48 grams. 

3. a) 100.0 mL water

4. 80 degrees C then 20 degrees C.

5. Saturated means that there is so much of a substance that you cannot dissolve anymore of it. An unsaturated solution is a solution that contains less dissolved solute than the amount that the solvent can normally hold at that temperature. 

6. a) 30 grams

    b) supersaturated

    c) 35 grams

7. a) The crystal will dissolve into the solution.

    b) The crystals will remain undissolved at the bottom of the solution. 

    c) Solid crystals will form and will settle to the bottom of the solution. 

8. 1.5 x 35g = 52.5% 

 

What did you learn from this lab about water and about process?

I learned that there might be stuff in different water substances, but it may not always be visible. I also learned that there are many different steps to the process, and that the process requires plenty of teamwork.

Water Testing Lab Report

Water Testing Lab Report

6.25.13

Lithium: Nicolette, Makena, and Nina

Dr. Forman 

Summer Chemistry 

It’s no myth, call us Lith. 

Don’t stop pour that drop, see that color change then stop. Get a table, write results, grab your group and then consult. Are there ions, are there not, it interests me a lot. 

The Abstract 

       The purpose of the water testing lab is to test water and to learn about precipitate, and to detect if there are any ions present that are not visible. The water testing lab included four main steps, unlike the foul water lab which included three. The four main steps of the water testing lab are: the calcium ion test, the iron ion test, the chloride ion test, and the sulfate ion test. Each test included five different samples which included: the reference, the control, the tap water, the ocean water, and the distilled water. Some of the sources reacted when dropping ions into the substance, while others did not react. We then found out that ions were present in some of the samples, while they were not visible in the other samples. I feel like my group and I bond really well, and teamwork helped us get past the many obstacles that we came through. 

Procedure

       My group and I came through obstacles such as there being left over residue in our wash plates, causing our samples to turn pink. Other than that, we had a very smooth and great lab experience. 

Calcium Ion Test

      Place 20 drops of distilled water into a 24-well plate.  Place 20 drops of reference solution (Ca Chloride) into a 24-well plate. Place 20 drops of control solution into a 24-well plate.  Place 20 drops of Tap water into a 24-well plate. Place 20 drops of Natural water into a 24-well plate. Add 3 drops of sodium carbonate test solution to each of the wells. Decide whether CA2+ cations are present and record your results. Discard the contents of the well plates and clean. 

Iron (III) Ion Test

                                         Place 20 drops of distilled water into a 24-well plate. Place 20 drops of reference solution (Ferric Nitrate) into a 24-well plate. Place 20 drops of control solution into a 24-well plate. Place 20 drops of Tap water into a 24-well plate. Place 20 drops of Natural water into a 24-well plate. Add one to two drops of potassium thiocyanate test reagent to each of the wells. Decide whether Fe3+ cations are present and record your results. Discard the contents of the well plates and clean.  

Before

After

                       Chloride Ion Test

                             Place 20 drops of distilled water into a 24-well plate. Place 20 drops of reference solution (Ca Chloride) into a 24-well plate. Place 20 drops of control solution into a 24-well plate. Place 20 drops of Tap water into a 24-well plate.Place 20 drops of Natural water into a 24-well plate. Add 3 drops of silver nitrate test reagent to each of the wells.Decide whether Cl- anions are present and record your results. Discard the contents of the well plates and clean. 

     

                       Sulfate Ion Test 

      Place 20 drops of distilled water into a 24-well plate. Place 20 drops of reference solution (Ferric Nitrate) into a 24-well plate. Place 20 drops of control solution into a 24-well plate. Place 20 drops of Tap water into a 24-well plate. Place 20 drops of Natural water into a 24-well plate. Add 3 drops of barium carbonate test solution to each of the wells. Decide whether SO4^2- anions are present and record your results. Discard the contents of the well plates and clean.

Results

Calcium Ion Test 

Iron Ion Test

Chloride Ion Test

Sulfate Ion Test 

Class Aggregated Data:

     In our group, chloride and sulfate ions were present in the ocean water. In the class data, some groups had calcium ions present in the ocean water. In our group, sulfate ions were present in the control, but some groups in the class chloride and iron ions were present in the control. In all groups, calcium, iron, chloride, and sulfate were all present in the reference. 

Lab Questions #1-4 p. 45

1. There was a reference solution and a blank used in each test so that you have something that you can use as a comparison. 

2. Some problems associated with the use of qualitative tests are that you might have contaminants leftover in your wash plates. 

3. These tests cannot absolutely confirm the absence of an ion because you may not be able to physically see the ions. 

4. Our observations may have changed if we had not cleaned our wells or stirring rods thoroughly after each test in ways that our samples might turn pink or change color. My group and I experienced this change in color within our samples.