Blog Question

First, you must create or examine a solubility curve graph when solving solution concentration problems. Then, the hard part comes to place when calculating the percent of mass. 

Blog Homework 9

C.5 #1-3 p.62

1.
a. The solution goes from being unsaturated to saturated.
b.














2.
a.













b.
     i.




 







  ii. 20 grams


3.
a.












b.












c. The models in 3a and 3b are different because the model in 3b is less concentrated. The molecules are also more spread out as a result the additional water that was added, whereas in 3a, there is less water and the KCL molecules are closer together.

Blog Question

With the chart on page 54, I was able to complete the solubility homework questions. Also, with the concept of students helping students I was capable of understanding the concepts and vocabulary terms much more efficiently. Therefore, answering the questions and completing the homework was simple because I really understood the information.

Homework Blog 8

C.2 #1-3 p.56

1.
a. 105 grams
b. 45 grams

2.
a. 10 grams
b. 20 grams

3.
a. 87.5 g KNO3
b. At least 80 g

ISCS #1-8 p.52

1. Because higher temperatures dissolve the solutes more easily.

2. 50 grams (look at the chart on page 54)

3.
a. 200 grams
b. 710 grams
c. 1,892

4.
a. 20- KNO3, NaCl, KCl
b. 80- KNO3, KCl, NaCl

5. Saturated - when there is too much chemical for the water. Unsaturated - contains less dissolved substance than it can hold.

6.
a. 30 grams
b. Supersaturated
c. 35 grams

7.
a. The crystals will dissolve into the unsaturated solution.
b. The crystals will remain undissolved at the bottom of the saturated solution.
c. Solid crystals will form and will settle to the bottom of the supersaturated solution.


8. 52.5% - 1.5 x 35g = 52.5%

Lab Report

Water Testing Lab

June 25, 2013

Julia, Clemmy, Kourosh

Dr. Forman

Purpose: The purpose of this experiment was to test for the presence of iron and calcium cations as well as chloride and sulfate anions.

Background/Significance: Through the process of testing water samples in order to discover cations and anions in the samples, we approached new, intriguing conclusions that also led us to classify qualitative and quantitative data within each procedure.

Abstract: After completing these experiments, I learned the importance of being cautious and careful in order to obtain the correct results. I also tested for the presence of cations and anions and observed in a way that would be efficient in the long run. My quantitative and qualitative data was successful and I learned many important lessons from this lab.

Procedure:

Calcium Ion (Ca²⁺) Test

1.     Place 20 drops of each sample (distilled water, reference, unknown, tap water, natural water) in a well plate

2.     Add 3 drops of sodium carbonate to each sample and record your observations

3.     Discard the contents and rinse the well plate

Iron (III) Ion (Fe³⁺) Test

1.     Place 20 drops of each sample (distilled water, reference, unknown, tap water, natural water) in a well plate

2.     Add 2 drops of potassium thiocyanate to each sample and record your observations

3.     Discard the contents and rinse the well plate

Chloride Ion (CI^-) Test

1.     Place 20 drops of each sample (distilled water, reference, unknown, tap water, natural water) in a well plate

2.     Add 3 drops of silver nitrate to each sample and record your observations

3.     Discard the contents and rinse the well plate

Sulfate Ion (SO₄^2-) Test

1.     Place 20 drops of each sample (distilled water, reference, unknown, tap water, natural water) in a well plate

2.     Add 3 drops of bacterium chloride to each sample and record your observations

3.     Discard the contents and rinse the well plate

Results:

Calcium Ion (Ca²⁺) Test

Solutions	Observations	Results
Reference:	Precipitate, cloudy	Yes
Control:	Nothing, clear	No
Tap water:	Nothing, clear	No
Natural (ocean) water:	Slightly cloudy	Yes
Distilled (blank) water:	Nothing, clear	No

Iron (III) Ion (Fe³⁺) Test

Solutions	Observations	Results
Reference:	Dark red	Yes
Control:	Light yellow	Yes
Tap water:	Nothing, clear	No
Natural (ocean) water:	Nothing, clear	No
Distilled (blank) water:	Nothing, clear	No

Chloride Ion (CI^-) Test

Solutions	Observations	Results
Reference:	White	Yes
Control:	Light yellow	Yes
Tap water:	Nothing, clear	No
Natural (ocean) water:	White, slightly cloudy	Yes
Distilled (blank) water:	Nothing, clear	No

Sulfate Ion (SO₄^2-) Test

Solutions	Observations	Results
Reference:	Yellow with tiny red dots	Yes
Control:	Murky, white, cloudy	Yes
Tap water:	Nothing, clear	No
Natural (ocean) water:	White, grey, cloudy	Yes
Distilled (blank) water:	Nothing, clear	No

Together as a group, we all worked very hard in order to obtain successful results.  We were all very organized and cooperated extremely well with one another. We did this by communicating and taking turns dropping different substances into the well plate. Although at first we were a little bit confused on what to do because of the numerous liquids we were given, together we re-read the procedures and followed them step by step. Overall, this was a very successful experiment and taught us all science skills as well as life skills. 

Overall class results: 

These results are important because it lets us compare each others work. It is also important to group the entire classes data together because it lets us check our work to see how accurate our experiments were. Opposed to establishing facts on one groups experiments, the graph allowed us to be able to study the data collected by our entire class. Overall, our we all developed close to the same results. 

1.    A reference solution and a blank were used in each test so you have something you can compare other samples to.

2.     If your well plate or pipette is contaminated, incorrect color changes might occur, precipitates may not form properly, or your sample will not react properly. Therefore, there are many possible qualitative testing issues that could occur.

3.     These tests cannot absolutely confirm the absence of an ion because in many cases you can not physically see the ion, so it is impossible to tell or judge the sample based on something that is not visible.

4.     If our tools were not properly cleaned, our samples could have had many qualitative testing problems. Incorrect chemicals would be mixed which could lead to improper reactions between chemicals or discoloration and many other issues. 

Homework Blog 7

1SBS 52 #25-34 

25. Qualitative tests are tests that identify the presence or absence of a particular substance in a sample. Quantitate tests determine the amount of a specific substance present in a sample.

26. A confirming test is a positive test that confirms that the ion in question in present.

27.

a. We used a reference solution because a reference solution is a solution of known composition used as a comparison. It is knows to contain the sought ion.

b. We used a distilled water-blank because it's known to not contain any ions of interest.

28. Yes, which means that the iron is present because the test was positive.

29. I would do the Tyndall effect and pass a light through the water to test if there the mixture is a suspension, solution or a colloid. 

      

30. Medicine is a colloid; therefore, it is not uniform and it's possible that you might only drink some of the minerals or solutes. So, must shake the bottle in order to mix everything together.

31. It's useful for element symbols to have international acceptance because this way no one can get confused and it can be read by anyone. 

32.

 

33. It isn't possible for water to be 100% chemical free because atmosphere gasses will always dissolve in water to some extent.

34. H20 is water which is a liquid that is made up of gasses, oxygen and hydrogen. Together they make a liquid at room temperature.

Blog Question

How does testing water help us?

We are able to understand the lab process as we brought together qualitative and quantitative data. This allows us to discover what substances may be in the water that appear to be pure. 

Homework Blog 6

ISBS #19-24 p. 51

19. Number of protons and neutrons needed for an electrically neutral atom:

a. Carbon: 6 protons, 6 electrons

b. Aluminum: 13 protons, 13 electrons

c. Lead: 82 protons, 82 electrons

d. Chlorine: 17 protons, 17 electrons

20. Are the following atoms electrically neutral?

a. Sulfur: no

b. Iron: no

c. Silver: yes

d. Iodine: no

21. Are the following atoms electrically neutral, an anion, or a cation?

a. anion

b. electrically neutral

c. electrically neutral

d. cation

e. cation

22. Was the electrical charge or lack of electrical charge for each particle in #21 from a neutral atom gaining electrons, losing electrons, or neither?

a. losing electrons

b. neither

c. neither

d. gaining electrons

e. gaining electrons

23. Symbol and electrical charge for the following atoms or ions:

a. H

b. Na+

c. Cl-

d. Al+

24. Name and formula for the ionic compound that can be formed from these cations and anions:

a. KI = potassium iodine

b. CaS = calcium sulfur 

c. FeBr = iron bromine

d. BaOH = barium oxygen hydrogen

e. NHPO = nitrogen hydrogen phosphorous oxygen

f. AlO = aluminum oxygen

Water Log

Blog Question

What are the values of reading about science?

Reading about science has enhanced my perspective on everyday life. Utilizing science to its fullest capabilities, I have learned how to cut down on the amount of water I waste in a day. Instead of using a conventional faucet in the sink, I personally insisted that my mom get a water-saving faucet that can save us up to almost 10 liters of water! Science has not only taught me how to be conservative, but it has opened my mind to new ideas and concepts that I would never have understood had I not read about science. 

Homework Blog 5

A.7 #1-7 p. 20-21

1. 10,175 L

2. 565 L

3. 

4. 1,493 L

5. 600 L = mean and 579 = median. 600 is the better representation. 

6. We water our yards year round because we live in a desert and also our class has larger yards then other areas.

7. The class average is closer to the national mean. 

ISBS #13-18 p. 50-52

13.  A molecular compound made of 2 atoms A and D 

14.   

a. Models representing elements: i, ii, vi

b. Models representing compounds: iii, iv, v

15. A chemical formula provides two pieces of information. Each word represents a different chemical substance and a chemical symbol represents each element at hand.

16. Elements and the number of atoms in the following substances:

a. Phosphoric acid - three hydrogen atoms, one phosphorus atom, four oxygen atoms

b. Sodium hydroxide - one sodium compound, one oxygen atom, one hydrogen atom

c. Sulfur dioxide - one sodium atom, two oxygen atoms

17. Drawings of molecules and their component atoms:

•                H2 + Cl2 --> 2 HCl

•                2 H2O2 --> 2 H2O + O2

•                c. a. 2 hydrogen + 2 chlorine --> 2 hydrogen and chlorine. b. 2 compounds of hydrogen and oxygen --> 2 water + 2 oxygen.

18.

a. Na9 HCO3 + HCl --> NaCl + H2O + CO2

b. C6 H12 O6 + O6 --> CO6 3 H2O