Friday 4/15/11

Friday during class we picked up pages 2-6 of the pH tutorial. We worked on pages 2, 3 and 4. These pages were all about how to tell the pH of something if you know the given [H+] and vice versa. In part one we learned how to predict the pH. If you have 1x10^-5 the predicted pH would be 5 and it would be an acid. If it was 1x10^-12 than the pH would be twelve and it would be a base. Part two we learned the inverse of it. If the given pH is 2 than the predicted [H+] would be 1x10^-2 and it would be a base. In part three we learned how to find the ph if the number x 10^x is more than one. You use your calculator, hit (-), than (LOG) and than enter your number, and than (-) and the exponent. Part 4 we learned the inverse of that, you use (LOG), (-) and than the given pH. Then we learned how to find if something is Neutral, Basic or Acidic just by looking at the [H+] and the [OH-]. If the [H+] is greater than the [OH-] than it is an acid. The reverse works in the opposite manner, respectively. Lastly we learned how to determine the pH of something if we know the pOH and vice versa. Basically, the two numbers need to add up to 14, so you can figure it out.

Thurs 4/14/11

I. a.) Picked up Tritaion problems worksheet b.) Went over number 3: -H2SO4 + 2NAOH ---> 2H2O + NA2SO4 -How many ml of 0.6 M H2SO4 are needed to neutralize 90 ml of 0.4 M NAOH? (MA x VA = MB VB) ---> 2 X 6M x VA = 0.4M x 90 ml II. a.) Went over more examples of the same types of questions from #3: -HCL + CA(OH)2 would be MA x VA = 2MB x VB -H3PO4 + NAOH would be 3MA x VA = MB x VB -H2CO3 + AL(OH)3 would be 2MA x VA = 3MB x VB III. a.) Watched a CSI episode for the rest of class discussing a case where a man got pushed into a pool of highly concentrated acid and then burned, boiled, and died within a period of minutes. We discussed how the investigators would need vinegar (a base) to neutralize the acid before being able to pull the man out of the pool, otherwise they would burn too. If they just used water, it would slowly lower the concetration of the acid, but never actually neutralize it. Mr. Tucker also made his point that the most important part of the episode was that the wild boar was in season and that was why we were watching this in chemistry class.

Friday, 4/8/11, Acids and Bases

This is a late post.....Mon and Tue are below:

Acids and Bases, 4/8/11
1. Went over the properties of acids and bases.

2. Took a partner quiz on acids and bases.

3. Took notes.

NOTES:
Part 1- The Simulation
1. List the molecules and/or ions present in the solution of HCl.
-H+ Cl- H20
2.List the molecules and/or ions present in the solution of NaOH.
-Na+ OH- H2O
3. What is the purpose of the phenolphthalein (phth)?
-it is an indicator (base/ OH- turns pink)
4. Why doesnt the phenolphthalein change colors when it is first added to the cup?
-Acid + pht
NO OH-
5. What is the reaction that is happening when the NaOH is added to the cup?
-Neutralization reaction, NaOH + HCl produces NaCl + H2O
6. What has to be true for the phenolphthalein to turn pink?
- OH- > H+
first slight pink
EQUIVALENCE POINT
4. Part 2 of the notes: We did a lab using the base NaOH and the acid HCl. In the lab we had to put 10drops of HCl into a paper cup with one drop of phth. Next we add 1 drop of NaOH into the cup and mix it around when we see the pink. We continued this procedure until the pink remained the color of the mixture. Here is my groups data:


Drops HCl (.40M) Drops NaOH (X M)
Trial 1 10 36
Trial 2 10 31
Trial 3 10 67
Trial 4 10 63

We then used the equation Macid x Drops acid = Mbase x Drops base to figure out the molarity of NaOH in each trial. Here are our results:
Trial 1- .11 Trial 2- .13
Trial 3- .06 Trial 4- .06
The average concentration of the NaOH was .18.
In our lab results we had deviant trials. You can disguard deviant trials however mention it.

Posted by Therese Snow at 8:21 PM 0 comments
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Labels: Acids and Bases, Snow

Acids and Bases

Hello Everyone! Happy Tuesday!

So we did a few things in class today, most of which have to deal with the things we have been doing in class (Titration and Titration labs).

1. We went over the homework from last night (Monday) which was the Titration lab #2. Many people may have finished in class, but those of you that didn't had to finish it for homework. If you were absent, make sure you get Mr. Tucker to stamp it in for you. Here are some of the answers we got when going over the lab:

The Molarity of the Base for: Trial 1 is .89 M

Trial 2 is .87 M

Trial 3 is .87 M

Trial 4 is .63 M

Trial 5 is .94 M

1. The known substance is the Molarity Acid (.4 M) and the unknown is the Molarity of the base.

2. You could make the argument that both trial 4 and 5 are deviant trials because they are not so similar to the original three. You could just as easily make the argument that they are close enough, and that they are not deviant trials.

3. (Molarity of base at top)

4. a) .84

b) Again, this depends on which side you argued if you said 4 and 5 were deviants, your average is approximately .877 or .88. If you said they were not deviants, it stays the same at .84M

5. Yes, you should throw out the deviant trials, but you should be sure to mention them in your report so that you do not make that mistake again, and just so you remember there was one or multiple with data that was far off.

2. We went over the beginning of Titration lab 3

3. We went back to our tables in our lab groups, put our safety goggles on, and began our labs.

Basically what we did was we did the same thing we had been doing, but with solid acid opposed to liquid acid, and measuring how much base was needed to turn a set amount of acid pink.

***Homework***

Finish lab questions and anything else you might not have finished in class

Other things to take note of:

Someone took Mr. Tucker's keys, and if you know anything about them, he would appreciate it very much if you let him know.

Also, If you want to sign up for the "Chemistry Challenge" there are still teams that are needed. So, if you want to participate in this, and get a 20/20 for a lab grade, feel free to sign up.

Mr. Tucker has been assuring us that it will be somewhere on the scale of ok to fun, so if you like this kind of thing, sign up!

Hope this is helpful!

Solubitity

Things we did today:

1) Assigned Blog assignments for this week

2) Checked in the homework (Titration Lab 1)

3) Went back to labs groups and did another

trial for the Titration lab

Formula: Moles of Acid (.40M) x Drops of Acid (10 drop) = Moles of base (Unknown) x Drops of NaOH

4) Gave us Titration Lab Two

5) Homework: finish lab and do post lab questions

Thursday, April 7th 2011- Emma N.

At the beginning of class, we picked up 4 note sheets to put in our journal titled "ACIDS/BASES" and we also went into our lab groups and each separately read a paragraph from our text book paper copies, and had to write the "GIST" (hence the title) of the section we read. Including writing key words we read, and writing a 20 word summary of what we read including the key words we had previously written. We shared our summaries with each other, while Mr. Tucker checked in our Venn Diagrams we had for homework about the difference between acids and bases, and then shared our summaries with the class.

Then we took some notes.

1. Acids

A. What are some properties of acids?

-tastes sour

-reacts w/ metal to create H2 (g)

-turn litmus paper red

-react w/ carbonates to create CO2 (g)

*** IMPORTANT -creates H+ in water

-pH UNDER 7

B. What happens when acids dissociate in water?

HCl--> H+ + Cl-

HNO3 --> H+ + NO3-

2. Bases

A. What are some properties of bases?

-tastes bitter

-turns litmus paper blue

-turns pht (phenolphthalein) pink

*** IMPORTANT -creates OH- in water

-pH ABOVE 7

B. What happens when bases dissociate in wateR?

NaOH--> Na+ + OH-

NH3--> Na4+ + OH- (trick one!!)

3. WEAK AND STRONG ACIDS AND BASES

-Strong acids& bases completely dissociate in water (split apart)

-Weak acids&bases only partially separate in water.

At the end of class Mr. Tucker handed us a notecard which we wrote A on one side and B on the other, and he asked us questions and we had to decided which it was A, for acid, or B, for Base.

We received no additional additional homework except to finish the lab reports on moodle which are due tomorrow (Friday, April 8th, 2011)

Thursday, March 24th 2011- Emma N.

Today when we came into class, we picked up two sheets titles "Thermochemistry Review" on the front table. Everybody who brought food for our food review day placed it on the back table, and taped their write ups about it above the food.

Mr. Tucker then stamped everyones homework- the Unit 10 chemistry practice. If you completed the 3 pages required (not the math or reading pages) then you received 3 stamps.

Next, we went over answers and asked questions while eating our delicious food, that our fellow classmates brought in for us. (see pictures above for part of homework)

Once we finished going over the chemistry practice, Mr. Tucker reviewed Energy Diagrams vs Heating curves. It is important to know that energy diagrams relate to endo/exothermic reactions. Exothermic reactions release heat, and endothermic reactions gain heat. (see pictures above)

After that, he handed out 2 sheets: "Thermochemistry Review"

And told us to STUDY FOR THE TEST!!

Tue, 3/22,Eman

Today we entered class with two sheets waiting to be picked up on the front desk. Two sheets titled Energy and Reactions 1. After grabbing those two sheets and taking a seat, Mr. Tucker had gone around and stamped the homework from the night before. Once that was done, he had gone over some problems from the night before. Here are some answers that we went over class (they might vary):

CALCULATIONS

1. Mass of original water
            101.66 g.
2. Mass of water from melted ice (subtract mass of ice in water from the original water)
            17.71 g.
3. Change in temperature of water
            13 degrees Celsius
4. Amount of heat lost by original
            5,524.2 J.
5. Heat Fusion for the Ice
            311.914 J/g

QUESTIONS

1.Is the process of the ice melting endothermic or exothermic?
            Endothermic. Heat is traveling on/into the ice.
2.Is the process of the ice freezing endothermic or exothermic?
            Exothermic. The energy is traveling out of the ice.
SKIP #3

            We then continued on to the worksheets we had picked up in class. We had done #1 a & b in class. These are the answers we got as a class for that sheet:

1. CH4 + 2o2 -> CO2 +2H2O
   a. 4.00 g of Methane (CH4) is allowed to burn according to the reaction above. The energy released by the reaction is used to head 800 grams of water from 15.0 degrees Celsius to 81 degrees Celsius.
            -Find the energy released by the reaction in kJ.
            800g x 4.18J/gºC x 66.4ºC = (app.) 222 kJ
            -Find the moles of CH4 burned.
            4.0g CH4 x 1mol/16.04g = .249 mol CH4
            -Find Delta H in kJ/mol (including the sign) for the reaction above.
            222kJ/.249 mols = 892 kj/mols

** remember  delta H (which is heat associated with reaction)/ 892 kj/mol
  
   b. In another experiment 1.55 g of CH4 is burned. How much energy would be released?
            1.55 g CH4 x 1 mol CH4/16.04 g CH4 x 892 kJ/1 mol CH4 = 86.197 KJ -> 86.2 kJ

By the time we had gone over these problems in class, we were instructed to finish the rest of the two sheets for homework!

Michelle - Monday March, 21

Today started out by picking up 2 sheets at the front of the room for the Heat of Fusion Lab. Then Mr. Tucker checked in the homework which was page 2 of Heat Calculations 2 and answered questions that the class had on it. After that we took a short quiz on thermochemistry that was similar to the notes we previously took in class on thermochemistry and the homework page.
Finally we conducted the Heat of Fusions Lab. The procedure to conduct the lab can be found on the journal page he handed to us in class. It looks like this.

While conducting the experiment we had to write down the lab data in our journals. Our lab group's data looked like this.

After filling out the data page, Mr. Tucker had us fill out questions 1-3 on the 2nd page of the Heat of Fusion Lab. In order to fill out these questions, the data be filled out. The numbers from our calculations can be found on the data page. Our calculations looked like this.

Lastly, Mr. Tucker handed out journal page 4, Heat Calculations 3 for homework. Journal page 4 and the Webassign are due tomorrow.

Andrew- Friday, March 18th, Chem Day

Today for class we went to the auditorium to watch Mythbusters for a chem day. The Mythbusters episode was called "Crime & Mythdemeaners" and had to do with different security systems. We had to fill out a sheet with 30 questions having to do with the video.

The first part of the episode had to do with a fingerprint lock. They tried different methods of copying a fingerprint in order to trick the fingerprint lock. One of the questions we had to answer was:

What material was most like human skin?

Ballistic Gel

Ballistic gel was used to make a fingerprint very similar to a human fingerprint so they could fool the sensor on the door.

The second part of the mythbusters episode had to do with thermal motion alarms. Thermal motion alarms take an average room temperature reading, and are set off when the temperature is changed by the presence of a person.

The third part of the mythbusters episode tested out an ultrasonic motion detector. The motion detector is set off when someone walks past it. The mythbusters thought that if the person is undetectable than the alarm would not go off. They tested this theory by having someone walk through the room with a big white sheet over them, and the alarm did not go off.

In the final part of the mythbusters episode the final myth had to do with filling up a safe with water than dropping an explosive with nitroglycerin into it making the door fly off with a huge explosion. This myth came from a movie where this was done, and the villain got away with the goods inside. After numerous failed attempts the mythbusters finally got everything to work our just how they wanted. At the end they finally dropped the explosive into the water like the movie, and a huge explosion made the door go flying. Everything on the inside of the safe was destroyed though so the movie was not too realistic.

Thursday, March 17th ( St. Patrick's Day)

Today in class, besides Mr.Tucker's cheesy jokes that he thinks are great, We took notes on Thermochemistry/Energy.

Here are the notes:
1. Temperature-

Average kinetic energy of the particles in a substance.

Units Used: Fahrenheit( we don't use this in class), Celsius and Kalvin.

2. Heat-

Transfer of Energy (joules).........Can be gained or lost.

Tuckers Joke: " There's also dominicks and walgreens".....yaaaa? no comment

3. Heat loss and Gain

Endothermic- Gaining heat

Exothermic- Loosing Heat.


In between notes we did a quick observation of Mr Tuckers " Magic Blocks." One block was wood and one was metal. The wood block was warm, compared to the metal block. After putting a piece of ice on both blocks, the ice melted faster on the metal block!! This was all due to the energy transfer.



Graph on page 2 of notes ( at top of blog):

Part1.A Heating and Cooling of a solid

Heat (q)= M * Cp ΔT (Tf-Ti)


Part2B Melting solid <-> Liquid freezing

Heat= M * HF

Part3C Heating/Cooling a Solid

Heat (q)= M * Cp ΔT (Tf-Ti)

Part 4D Boil a liquid <-> Gas condenses

Heat= M * HV ( Heat Vaporization )

Part5E Heating/Cooling a Gas

Heat (q)= M * Cp ΔT (Tf-Ti)

Wednesday 3/16/2011

At the start of class we picked up 3 sheets:

Graph, Pre-Lab Questions, and Lab sheet.

Then Mr. Tucker explained the lab, and checked in our HomeWork.

After that we went back into our lab groups and started working on the lab.

You record your data and follow the lab instructions. Also the rest of the lab and graph sheet for the lab are due for homework.

Fri, Kin./EQ Review / Tucker

Sorry for the late post for Thu...internet issues in hotel.  GOOD LUCK STUDYING THE MATERIAL AND SEE YOU ON MONDAY!!  Mr. Tucker

Kinetics & Equilibrium Review Answers

1.       Particles COLLIDE in the correct orientation and with enough force

2.       As temperature increases particles move faster and collide more often and with more force

3.      Surface area, concentration, and catalysts

4.      Surface area is increased

5.      Decrease temperature, decrease concentration of reactants, decrease surface area…..all would lead to fewer COLLISIONS

6.      The reactions continue at equilibrium….they are just at the same rate.

7.      K=  [H2O]² / [HCl]⁴…….others are not used b/c liquid and solid

8.      0.09M

9.      If O2 is removed the reaction shifts to the LEFT (to add more O2)
if reaction shifts left, then NO2 and O2 increase and NO3 decreases on the graph

10. 

a)       Opposite of remove H2O is ADD H2O so shift left

b)        For this problem, write the word HEAT on the reactant side (left).
  the opposite of decrease temp in INCREASE TEMP so shift left towards the heat

c)      No Shift, SiCl4 is a liquid

d)      Opposite of Remove HCl is ADD HCl, so shift right

e)      When the word pressure is mentioned count the moles of gas on each side of the equation…..2moles gas on left, 4 moles of gas on the right…..Opposite of increase pressure is decrease pressure so go towards the side with fewer moles of gas…..shift left

11.   Increase temp, shift left

Add more S, No shift
Decrease H2-  shift left
Add a catalyst……  skip, do not worry
Increase volume…..skip, do not worry

12.   K = [H2S] / [H2]

13. 
a)  True, if K is greater than 1 the products are favored  (K = P/R)

b)  False, if K is less than 1, the reactants are favored

c)  Temp does not affect K, just concentrations of P and R

14.   

a)  N2(g) + 2H2(g)  à  2NH3(g)

b)  O2(g) + C(s)  à  CO2(g)…….this question is trick, but the C must come from    somewhere and the reason it is excluded from the K equation is b/c it is a solid

15.  First, find the concentrations of all substances by dividing mols by 5L

            [NH3] = 0.40M,  [H2] = 0.60M,  [N2] = 0.20M

        Then, figure out the K equation……K = [NH3] / [N2] x [H2]³

            K=  3.7

Thu, Kin./EQ Practice / Tucker

Chemistry Practice ANSWERS:

Math Skills:
From top left to right
1.  2.22
2.  125
3.  8
4.  1.17E-5
5.  1.33
6.  0.942
7.  10
8.  0.868
9.  7.13E-5

Reading for Information:
a)  about 98.6F, Homeostasis…like hair and shivering
b)  about 98.6F, Homeostasis, like sweating
c)  Yes, body keeps changing in response to external conditions
d)  House heats up, thermostat increases, air conditioner turns on, House cools down, Thermostat decreases, air conditioner turns off
e)  Body changes OPPOSITELY in response to stresses(changes) on it…it tries to fix itself.

Data Interpretation:
a)  Temp, Time
b)  Amounts of A and B
c)  about 1-2seconds
d)  Inverse, as T goes up, time goes down
e)  Cannot predict, A may not react with C

Unit 11 Problems Broken Down:
1.
a.  K=  [P] / [R]
b.  K = [NO2]² x [Br₂] / [NOBr]²c)  NOBr-  109.9g/mol,  NO- 30g/mol, Br2-  159.9g/mol
d)  NOBr-  0.910 mol,  NO- 0.333 mol, Br2- 0.625 mol
e)  5L
f)  mol / L
g)  NOBr-  0.182M,  NO- 0.0667M, Br2-  0.0125M
h)  K=  0.00168

2.
a)  double arrow
b)  forward reaction = reverse reaction, concentrations of reactants and products are constant
c)  +, reactant side…….do not worry, I will always tell you what side the heat is on for now
d)  2mols reactant, 3 mols product
e)  More,  Less
f)  GIVEN
g)  add SO2, right, SO2 and O2, SO3, more moles gas, increase
h)  decrease O2, left, SO3, SO2 and O2, less moles gas, decrease
i)  decrease temp, right, SO2 and O2, SO3, more moles gas, increase
j)  increase pressure, right, SO2 and O2, SO3, more moles gas, increase

Thu, 3/3, Tucker

Today each lab group performed a short lab involving a reaction with alka-seltzer and water.  The reaction produced a gas and when this reaction occured in a flask with a balloon placed over the top of the flask, we were able to time the reaction...how long did it take for the balloon to inflate?  Since different groups investigated different independent variables, we then shared data/conclusions with the class.  The three labs are outlined below:

WE JUST WROTE THIS LAB IN OUR JOURNALS!!

Lab 1:
Procedure:  Place 1/4 alka seltzer tablets in 25ml of water in a 50ml flask and place a balloon over the top of the flask.  Time how long it takes for the balloon to inflate.  Repeat with 1/2 and full tablets.
Data:
1/4tablet-  45sec
1/2 tablet-  14sec
1 tablet-  6sec
Conclusion:  As concentration increases, so does the speed of the reaction

Lab 2:
Preocedure:  Place 1/2 alka seltzer in in 25ml of water in a 50ml flask and place a balloon over the top of the flask.  Time how long it takes for the balloon to inflate.  Repeat with a crushed alka-seltzer (which has more surface area!)
Data:
1/2 tablet -  16sec
1/2 tablet crushed- 5sec
Conclusion:  As surface area increases, so does the speed of the reaction

Lab 3:
Procedure:  Place 1/2 tablet of alka-seltzer in 25ml of room temperature water (22 degreesC) in a 50ml flask and place a balloon over the top of the flask.  Time how long it takes for the balloon to inflate.  Repeat this with 5degreesC water and 50 degreesC water.
Data:
5C- 2min, 20sec
22C-  20sec
50C-  4sec
Conclusion:  As temperature increases, so does the speed of the reaction

The independent variables for the lab were concentration, surface area, and temperature
The dependent varibale for the lab was time / speed of the reaction
The controlled varibales for the lab were the size of flask, type of tablets, and amount of water.

Kyle-Wednesday, 2/23 Solubitity

1) We got our ChemThink Homework stamped by Mr. Tucker.

2) We went over problem #5 on the Solubility Practice worksheet.

• NaNO3(aq) + AgNO3(aq) ------> NaNO3(aq) + AqNO3(aq)

• Their is no reaction because all four coumpounds are soluble in water(aq).
• You just put a line through the problem or say NR.

3) We also did a Solubility Lab in which we mixed six different solutions with each other and we watched to see if their was a reaction. We made a 6 by 6 grid with the solutions and their reactions. If their is an X through one that means we didn't try the solutiuon. NR means no reaction and Rxn means a reaction occured. Here is the chart we did in class.

	MgCl2	K3PO4	NaNO3	Na2CO3	AgNO3	CuSO4
MgCl2	X	X	X	X	X	X
K3PO4	Rxn-Cloudy color	X	X	X	X	X
NaNO3	NR	NR	X	X	X	X
Na2CO3	Rxn-Cloudy color	NR	NR	X	X	X
AgNO3	Rxn-Cloudy color	Rxn-turned yellow	NR	Rxn-Cloudy color	X	X
CuSO4	NR	Rxn-Cloudy color	NR	Rxn-Cloudy color	NR	X

Here are some examples of a reaction taking place. Make sure to use the Solubility Rules worksheet as a cheat cheat. Notice how one product is a solid(s) and the other is aqueous(aq).

1. K3PO4(aq) + 3MgCl2(aq) ------> 6KCl(aq) + Mg3(PO4)2(s)
2. Na2CO3(aq) + MgCl2(aq) ------> 2NaCl(aq) + MgCO3(s)
3. 2AgNO3(aq) + MgCl2(aq) -------> 2AgCl(s) + Mg(NO3)2(aq)
4. 3AgNO3(aq) + K3PO4(aq) -------> Ag3PO4(s) + KNO3(aq)
5. 3CuSO4(aq) + K3PO4(aq) -------> Cu3PO4(s) + 3KSO4(aq)

Now here are a couple examples of no reactions or NR. Notice how the products are both aqueous(aq).

1. 2NaNO3(aq) + MgCl2(aq) -----> 2NaCl(aq) + Mg(NO3)2(aq)
2. AgNo3(aq) + NaNO3(aq) -------> AgNO3(aq) + NaNO3(aq)

4. The last thing we did today was get a sheet called Solution Stoich 1. Mr. Tucker went over problem #3a. For homework we have to try problem 3b.

3a. What volume of 0.150 M AgNO3 is needed to react with 45.0 mL of 1.50 M CaCl2?

3b. What mass of AgCl will be produced when 150mL of 0.650 M CaCl2 reacts?

Natalie- Tuesday, 2/22

1) We picked up one sheet: ChemThink Precipitate Lab

2) We went over lab quiz we took on friday

• Molarity= unit of concentration
• Use formula to determine how many mols of solute needed to make 0.15 M of solution
• If you need help with the formula use this video as a reference: http://www.youtube.com/watch?v=8oTqwBAvbnY&feature=fvwrel
• 
  

  .015 mol NaCl	58.44g NaCl
  	1 mol NaCl

  
  
• Fill beaker with 50 mL of water
• Then mix in .88g of Solute (NaCl)
• Then fill rest of the beaker to 100 mL

3) Went through IV. Solubility Notes

• 
• Soluble in water= dissolves in water (aqueous)
• In soluble= does not dissolve in water (solid)
• There are some exceptions though, mentioned on the sheet

4) Went through V. Solubility Practice #1-3:

• 
• If the balanced equation has aqueous on both sides, then no reaction has taken place

5) Homework are questions #1 and #2 on the ChemThink precipitate lab sheet we picked up in

class. Use www.chemthink.com to answer the questions under Solubility

Shayne - Friday, 2/18

I. We picked up two sheets at the beginning of class - (Molarity 2 and Reaction Stability 1)

II. We went through the Molarity 2 notes:

EXAMPLES:

1.) What will be actually present in the solution when each of the following is added to water?

a. KCL ----------> K+ (aq) plus Cl- (aq)
b. NaNO3 ----------> Na+ (aq) plus NO3- (aq)
c. C2H6O ----------> C2H6O (aq)

3.) Calculate the mlarity (M) of the following solutions. (M = Mol/L)

a. M = 0.0346 Mols/0.250 Liters = 0.138M
b. (405 g NiCl2 X 1 mol NiCl2)/129.59 g NiCl2 = 3.12524 mols NiCl2
M = 3.12524 Mols/7.54 Liters = 0.414M
c. (22.57 g H2SO4 X 1 mol H2SO4)/98.09 g H2SO4 = 0.23009 mols H2SO4
100 Ml = 0.1 L so.....
M = 0.23009 Mols/0.1 L = 2.301M

5.) Calculate the mass of the solute present in the following solutions.

a. Mol = M x L so...
0.125M x 0.200L = (0.25 Mols Kbr x 119 g KBr)/1 Mol KBr = 2.98 g KBr
b. Mol = M x L so...
Mol = 0.150M x 0.1L
(0.015 Mols Na2SO4 x 126.05 g Na2SO4)/1 mol Na2SO4 = 1.89 g Na2SO4

III. We took a lab test in groups of two, having to make a solution of 0.15M of NaCl and show calculations

Th-2/17-Gabuzzi

1. We picked up 2 sheets.

• Molarity 1
  
• Dissolving 1

2. We took a quiz on the mixtures notes we took on wednesday.

3. We then review the different types of substances and mixtures.

4. We finished the Solution Notes

III. Solutions . (we used salt water as an example)

A. Solute- dissolved (salt)

B. Solvent- doing dissolving (water)

C. Solution- solute and solvent (mixture of salt water)

D. Concentration of solution:

M=molarity

M= 1 mol solute per liter of solution. 1.0m=1 moler.

E. Preparation of solution:

1. find total volume
2. fill container 1/2 way with solvent
3. add a solute and mix
4. fill container to desired volume with solvent

We filled out the Molarity 1 and Dissolving 1 Worksheets (see photos at top for answers)

Homework: Finish Molarity 1 worksheet or we will be doing webassigns for the rest of the year.