today in chemistry class we started by watching a cool video explaining Le Chatelier's Principle, he states that when a system is at equilibrium and subjected to a stress, the system will adjust to relieve the stress but changing concentrations by adding or removing products or reactants to the reaction, changing the pressure of gaseous reactants and products and changing the temperature will affect the outcome of the equilibrium and therefore will have to first determine what needs to happen for the reaction to get back to equilibrium.
Change in concentrations example:
A + B <--> C
- if you add more A, the equilibrium shifts to the right producing more C
- if you add more B, the equilibrium shifts to the right producing more C
- if you add more C, the equilibrium shifts to the left producing more A & B
Change in pressure
A + B <--> C
- an increase in pressure will cause a shift to the right, producing more C (product)
Change in temperature
A + B <--> C
- the shift caused by a change in temperature depends whether the reaction is exothermic or endothermic
- increasing the temperature will cause a shift to the left using the excess heat and an increase in forward reaction would produce even more heat because it is exothermic reaction.
Thus conclude me scribe post aaaaaaaarrrrrrr....
have you guys seen a blue folder with killer whales? waaaaahhh please give it to me if you find it because all my chem. stuff are in there waaaaaaaahhhhhhhhhh......KEER i choose you to be the next scribe
ruschev
Monday, April 30, 2007
Wednesday, April 25, 2007
April 25, 2007
Soooo im today's scribe :) buahahah no one will ever know who i am... ?!?! or will they?! k whatever. i really dont care. but it was funny when he tried to figure out who i was :) sneaky lil me. okay anyways. back to chemistry...
Ms K handed our 4 & 5 questions back and we went over them since some had trouble...(me). haha. k yeea anyways. The steps are on the previous blog Ms K had posted up for us.
We then went over the homework assigned yesterday in the yellow booklet questions 1-6. So if you weren't able to keep up or you either didn't do them. I think you should go over the slide and copy BUT understand what is going on as well :))
Another thing we did today was something new. whoo hoo!
Reaction Quotient = Q or we know it as TRIAL Kc
reaction quotient helps us figure out whether or not the reaction is favoured (forward or reversed) in order for equilibrium to happen.
Previous slide will help you understand a lil more on what is favoured between Q and K.
There is also an example in the white booklet which will also help you understand this concept of Reaction Quotient. It's quite easy once you read over and do the work assigned
BTW: there's homework :) YAY! Lesson 3 Homework Assignment 6-10.
next scribe i will choose will be...ROMINA
Ms K handed our 4 & 5 questions back and we went over them since some had trouble...(me). haha. k yeea anyways. The steps are on the previous blog Ms K had posted up for us.
We then went over the homework assigned yesterday in the yellow booklet questions 1-6. So if you weren't able to keep up or you either didn't do them. I think you should go over the slide and copy BUT understand what is going on as well :))
Another thing we did today was something new. whoo hoo!
Reaction Quotient = Q or we know it as TRIAL Kc
reaction quotient helps us figure out whether or not the reaction is favoured (forward or reversed) in order for equilibrium to happen.
Previous slide will help you understand a lil more on what is favoured between Q and K.
There is also an example in the white booklet which will also help you understand this concept of Reaction Quotient. It's quite easy once you read over and do the work assigned
BTW: there's homework :) YAY! Lesson 3 Homework Assignment 6-10.
next scribe i will choose will be...ROMINA
Tuesday, April 24, 2007
Scribe post
Today all we did was attend a assembly that was reminder to all grade 12's to graduate. We were assigned 1-6 in the yellow booklet under Chem Equilibrium assignment. And a reminder to the people that skipped the class, Hand in Equilibrium lab & 4 and 5 from Lesson 3.
The next scribe is BOOT5.................
The next scribe is BOOT5.................
Monday, April 23, 2007
Blog: Monday, April 23, 2007.
What we did Monday, April 23, 2007.
REMINDER: "Grade 12 Chemistry: Chemical Equilibrium Experiment" is due.
- We started off the class by reading from the "Grade 12 Chemistry: Chemical Equilibrium" booklet. Page 11 - Page 13.
Page 11, "Calculating Equilibrium Concentration."
If the equilibrium constant is given, the concentration of one of the reactants or products can be calculated if the other values are given as well.
Examples & Solutions are given.
- Then we practiced with problems provided in our yellow booklets labeled "Equilibrium Project Assignment."
Page 4, Lesson 3 Homework Assignment.
We answered #1 - #3 in class.
Answers to #1, refer to page 3 & 4 on Ms. Kozoriz's "Monday ICE Problems."
Answers to #2, refer to page 5 & 6 on Ms. Kozoriz's "Monday ICE Problems."
Answers to #3, refer to page 7 & 8 on Ms. Kozoriz's "Monday ICE Problems."
Finish "Lesson 3 Homework Assignment," #4 & #5
That's the end of what we did in class.
The next scribe is: Allen.
An Analogy for Equilibrium Reaction
Today in class we did a lab regarding the chemical equilibrium and formed an analogy for an equilibrium reaction. Our objective was to illustrate the experimental conditions necessary to have a system of experimental equilibrium, the effect of applying stress to a system in equilibrium, and to illustrate graphically the changes which lead to the establishment of equilibrium.
In order to find our objective, we used materials such as two 25ml graduated cylinders, colored water, and two different diameter drinking straws. We filled the first beaker with 25ml of water and left the other one empty and proceeded to transfer waters to and from each cylinder using their designated straws until we established an equilibrium. We added 5ml to the first beaker, then repeated the experiment.
We plotted the values on a chart which we then graphed.
tank u hab a nice dey!
-jhunD
In order to find our objective, we used materials such as two 25ml graduated cylinders, colored water, and two different diameter drinking straws. We filled the first beaker with 25ml of water and left the other one empty and proceeded to transfer waters to and from each cylinder using their designated straws until we established an equilibrium. We added 5ml to the first beaker, then repeated the experiment.
We plotted the values on a chart which we then graphed.
tank u hab a nice dey!
-jhunD
Thursday, April 19, 2007
Wednesday 18 ,2007 ( TEST)
Hello guys . We had Kinetics Test today so nothing much to tell about. After we handed in the test, Ms. K gave to us a new Unit booklet about Chemical Equilibrium . SO yah , that's all for today scribe . The next scribe will be jhun.
Tuesday, April 17, 2007
Test Preparations
Today in class we went over the Reaction Rates review sheets that we were given. We were also given pages in the textbook to read in order to aid us in our test preparations, pg 395-409 in the Chemistry text book.
Next scribe is Beautiful Soul.
Next scribe is Beautiful Soul.
Monday, April 16, 2007
Last topic in Kinetics
Ms. K discussed our last topic in Kinetics and she gave us a hand out of our review sheet.
Rate law
It is an expression which relates the rate of a reaction to the concentration of the reactants.It helps us to calculate the rate of a reaction with the given concentrations of reactants.
A--->products
Rate=-ΔA/Δt
*rate of consumption a is directly proportional to its concentration,the faster a is consumed the lower its concentration.
formula: Rate=k[A]x
where in:
k is the constant of proportionality
A is the concentration of A
x is the power,called the order of the reaction
*rate constant can only be determined experimentally
*the rate constant is specific for each reaction at a specific temperature,since its value depends upon the size, speed and types of molecules in the reaction
*TEMPERATURE is the only factor that affects the rate constant
REACTION ORDER
The order of reaction indicates how concentration of reactants affects the rate of reaction.
In a first order reaction, if the concentration of A were doubled, the rate would be doubled.If the concentration were tripled,the rate would be tripled.
Ex.
rate= k[A]2[B]3 then the overall order is 5
CALCULATING RATE ORDERS
The rate law can only be determined experimentally.Even the rate of formation of the products and the rate of consumption of reactants is related to their stoichiometry,the law cannot usually be determined from the molar coefficent.
RATE LAW AND STOICHIOMETRY
(base it on your copy,not that hard eniweys)
RATE LAW AND REACTION MECHANISM
(even this one we did this one already)
***Reminder: We will be having our test on wednesday and don't forget to answer the review sheet ok??!!!.
the next scribe would be sergio
Rate law
It is an expression which relates the rate of a reaction to the concentration of the reactants.It helps us to calculate the rate of a reaction with the given concentrations of reactants.
A--->products
Rate=-ΔA/Δt
*rate of consumption a is directly proportional to its concentration,the faster a is consumed the lower its concentration.
formula: Rate=k[A]x
where in:
k is the constant of proportionality
A is the concentration of A
x is the power,called the order of the reaction
*rate constant can only be determined experimentally
*the rate constant is specific for each reaction at a specific temperature,since its value depends upon the size, speed and types of molecules in the reaction
*TEMPERATURE is the only factor that affects the rate constant
REACTION ORDER
The order of reaction indicates how concentration of reactants affects the rate of reaction.
In a first order reaction, if the concentration of A were doubled, the rate would be doubled.If the concentration were tripled,the rate would be tripled.
Ex.
rate= k[A]2[B]3 then the overall order is 5
CALCULATING RATE ORDERS
The rate law can only be determined experimentally.Even the rate of formation of the products and the rate of consumption of reactants is related to their stoichiometry,the law cannot usually be determined from the molar coefficent.
RATE LAW AND STOICHIOMETRY
(base it on your copy,not that hard eniweys)
RATE LAW AND REACTION MECHANISM
(even this one we did this one already)
***Reminder: We will be having our test on wednesday and don't forget to answer the review sheet ok??!!!.
the next scribe would be sergio
Sunday, April 15, 2007
Kinetics Assignment #4
Friday, April 13, 2007
Ms. K was not around and we have a substitute, Ms. McQueen. We just went over the Kinetics assignment # 4 and she gave us some hand outs on RATE LAW.
So for those who missed class and wasn't able to get the answer to the Kinetics assignment #4, here you go:
1. 2H2O2 ----> 2H2O + O2
2. (a) 2P + Q + S ----> R + T + W
(b) Slow
(c) Both P & Q are present in the rate limiting step and since S is not in the rate limiting step it does not affect the rate of of the net reaction. Only the reactants in the rate-
limiting step will significantly affect the rate of the reaction.
3. (a) The RDS is step 1 : C6H6 + NO2+ ----> C6H6NO2+
Because it's the slow reaction.
(b) C6H6 + NO2+ ----> C6H6NO2+ + H+
(c) H2SO4 is introduced in step 2 and is unchanged at the end of the reaction. H2SO4 is most likely a catalyst sine it speeds up the reaction but is unchanged at the end of the reaction
(d)
Step 1 Ea 1 Increase (longest)
Step 2 Ea 2 Decrease (smallest)
Step 3 Ea (small)
4. (a) The rate Increase
(b) p + 3Q ----> Z + Y
(c) The RDS is Step 2: A + 2Q ----> X + Y because it has the lowest rate of reaction.
so thats about it. see you all monday.....
next scribe is forgHa_baybhie
Ms. K was not around and we have a substitute, Ms. McQueen. We just went over the Kinetics assignment # 4 and she gave us some hand outs on RATE LAW.
So for those who missed class and wasn't able to get the answer to the Kinetics assignment #4, here you go:
1. 2H2O2 ----> 2H2O + O2
 | |
2. (a) 2P + Q + S ----> R + T + W
(b) Slow
(c) Both P & Q are present in the rate limiting step and since S is not in the rate limiting step it does not affect the rate of of the net reaction. Only the reactants in the rate-
limiting step will significantly affect the rate of the reaction.
3. (a) The RDS is step 1 : C6H6 + NO2+ ----> C6H6NO2+
Because it's the slow reaction.
(b) C6H6 + NO2+ ----> C6H6NO2+ + H+
(c) H2SO4 is introduced in step 2 and is unchanged at the end of the reaction. H2SO4 is most likely a catalyst sine it speeds up the reaction but is unchanged at the end of the reaction
(d)
Step 1 Ea 1 Increase (longest)
Step 2 Ea 2 Decrease (smallest)
Step 3 Ea (small)
4. (a) The rate Increase
(b) p + 3Q ----> Z + Y
(c) The RDS is Step 2: A + 2Q ----> X + Y because it has the lowest rate of reaction.
so thats about it. see you all monday.....
next scribe is forgHa_baybhie
Thursday, April 12, 2007
Collision Theory and Reaction Mechanism
Hello everyOne, soRry if this blog is late...
What we did in class this morning is that Ms. K helped us to answer all the questions on the sheets the she gave to us. about potential energy diagrams and factors affecting rate. Just look at the slideshow for the answers that you didnt get..
*It sticks to my mind that the addition of CATALYST increase the rate and the activation energy become lower, like what happened to the experiment of ms. K last wednesday.
Then, she gave a new sheet about Collision and Reaction Mechanism and its glad that she explained it very clear... Like theres some new terms that we need to remember, like the
->BIMOLECULAR it means that its a combining of two particles.
->SIMPLE REACTION is the reaction which place in one elementary step.
->COMPLEX REACTION is the reaction which take place in more than one step..
Hint: all Complex Reaction contain at least one reaction intermediate.
->REACTION INTERMEDIATES products of one reaction that immediately become reactants in another reaction.
->MECHANISM is the steps in which a reaction occurs.
->RDS or RATE DETERMINING STEP the step with the slowest rate.
Ms. K also left us an assignment, just to remind you guys its assignment #4.
I didnt wrote too much because all the details is in the slideshow, just look at it.
Thenkzz...
The next scribe would be phoebes3...
What we did in class this morning is that Ms. K helped us to answer all the questions on the sheets the she gave to us. about potential energy diagrams and factors affecting rate. Just look at the slideshow for the answers that you didnt get..
*It sticks to my mind that the addition of CATALYST increase the rate and the activation energy become lower, like what happened to the experiment of ms. K last wednesday.
Then, she gave a new sheet about Collision and Reaction Mechanism and its glad that she explained it very clear... Like theres some new terms that we need to remember, like the
->BIMOLECULAR it means that its a combining of two particles.
->SIMPLE REACTION is the reaction which place in one elementary step.
->COMPLEX REACTION is the reaction which take place in more than one step..
Hint: all Complex Reaction contain at least one reaction intermediate.
->REACTION INTERMEDIATES products of one reaction that immediately become reactants in another reaction.
->MECHANISM is the steps in which a reaction occurs.
->RDS or RATE DETERMINING STEP the step with the slowest rate.
Ms. K also left us an assignment, just to remind you guys its assignment #4.
I didnt wrote too much because all the details is in the slideshow, just look at it.
Thenkzz...
The next scribe would be phoebes3...
Tuesday, April 10, 2007
April 10, 2007
Okay, so today in class we were given a hand out "Chemical Kinetics - Reaction Coordinate Diagrams" it basically defines the meaning of both Exothermic and Endothermic reactions.
Exothermic Reaction - In an exothermic reaction, the products possess less energy than the reactants. Also, during an exothermic reaction, heat is lost from the system and the change in heat is a negative value.
Endothermic Reaction - In an endothermic reaction, the product possess more potential energy than the reactants. This energy is absorbed from the surroundings, which increases the systems energy content. Which leads us to having a positive number when changing of heat.
Okay, now for the assignments. Just last week, we were given a yellow booklet which consisted of Kinetic Assignments 1 through 5. We were given a few minutes in class to complete assignment 2 numbers 1-3. Afterwards, we went over them.
Answers to Kinetics Assignment #2
1a. Activation Energy: 25kJ
b. Hproduct - Hreactant
35kJ - 20 kJ = +15kJ
c. This is an endothermic reaction
2a. Activation Energy: -150kJ
b. 25kJ - 100kJ = -75kJ
c. This is an exothermic reaction
d. Reverse reaction: 250kJ - 25kJ = +225kJ
3a. Activation Energy: 10kJ
b. 15kJ - 35kJ = -20kJ
c. This is an exothermic reaction
d. Reverse reaction: 45kJ - 15 kJ = +30kJ
Thats pretty much all we've done so far in the booklet.
Kay, so she also gave us a hand out of reaction rates. So just work on it.
Other then that, if you haven't completed the Kinetics Assignment (graphing) given out yesterday in class, please have it done as soon as possible.
Okay, so that's all for now. The next blogger will be yhO-eE
Exothermic Reaction - In an exothermic reaction, the products possess less energy than the reactants. Also, during an exothermic reaction, heat is lost from the system and the change in heat is a negative value.
Endothermic Reaction - In an endothermic reaction, the product possess more potential energy than the reactants. This energy is absorbed from the surroundings, which increases the systems energy content. Which leads us to having a positive number when changing of heat.
Okay, now for the assignments. Just last week, we were given a yellow booklet which consisted of Kinetic Assignments 1 through 5. We were given a few minutes in class to complete assignment 2 numbers 1-3. Afterwards, we went over them.
Answers to Kinetics Assignment #2
1a. Activation Energy: 25kJ
b. Hproduct - Hreactant
35kJ - 20 kJ = +15kJ
c. This is an endothermic reaction
2a. Activation Energy: -150kJ
b. 25kJ - 100kJ = -75kJ
c. This is an exothermic reaction
d. Reverse reaction: 250kJ - 25kJ = +225kJ
3a. Activation Energy: 10kJ
b. 15kJ - 35kJ = -20kJ
c. This is an exothermic reaction
d. Reverse reaction: 45kJ - 15 kJ = +30kJ
Thats pretty much all we've done so far in the booklet.
Kay, so she also gave us a hand out of reaction rates. So just work on it.
Other then that, if you haven't completed the Kinetics Assignment (graphing) given out yesterday in class, please have it done as soon as possible.
Okay, so that's all for now. The next blogger will be yhO-eE
Monday, April 9, 2007
Kinetics
Today we went over the Kinetics Assignment #1; and then we had to do another assignment in class.
the answers for the yellow booklet assignment are:
1.a) -2.6 g/min
b)-2 g/min
2.a)-0.000013 mol/Ls
b)-0.00006 mol/Ls
c)since it's 1:1 ratio it's the same for both of them, which is 0.10 mol/Ls for CO & CH4
3.a){basically you take the mass of beaker and contents which is given and subtract it from the first one, that's why the first square would be 0.00 and so on....}
b)0.248 g/min
c)i>0.0077 g/min
ii> -0.02167 g/min
4. for NO2=0.2 mol/Ls
for O2= 1 mol/Ls
5.a) 0.1125 mol/Ls O2
b) 0.135 mol/Ls H2O
c) 0.09 mol/Ls NO
****
Don't forget to finish the homework(assignment #1)
the next scribe is kayyy
the answers for the yellow booklet assignment are:
1.a) -2.6 g/min
b)-2 g/min
2.a)-0.000013 mol/Ls
b)-0.00006 mol/Ls
c)since it's 1:1 ratio it's the same for both of them, which is 0.10 mol/Ls for CO & CH4
3.a){basically you take the mass of beaker and contents which is given and subtract it from the first one, that's why the first square would be 0.00 and so on....}
b)0.248 g/min
c)i>0.0077 g/min
ii> -0.02167 g/min
4. for NO2=0.2 mol/Ls
for O2= 1 mol/Ls
5.a) 0.1125 mol/Ls O2
b) 0.135 mol/Ls H2O
c) 0.09 mol/Ls NO
****
Don't forget to finish the homework(assignment #1)
the next scribe is kayyy
Sunday, April 8, 2007
CHEMICAL KINETICS
Today we spend the time going over the answers of the homework(pg.424-425;Q's.17-23), and the answers should be on the blog.
Then we had a new lesson; and here are the sheets:
This is Kinetis Assignment #1 which is homework:
Thursday, April 5, 2007
Wednesday' class: Lab continuation
Today in chem we did another lab this time it was about how temperature affected the rate of reactions. This lab did not go so well but i knew already that the temperature does affect the rate of reactions, i think that the temperature makes everything move after therefore making reactions occur faster. Catalysts affect the rate of reaction by lowering the activation energy level and increasing the rate of reaction.
Zahra was kind enough to scribe for Thursday's class.
Zahra was kind enough to scribe for Thursday's class.
Tuesday, April 3, 2007
The Scribe.. <- =D...
Well Today in class we a lab... On the Nature of Reactants..
We did part one and part two
In part one we tested the reactiblilty of certain substances in different solutions... And the time that it took for reactions to occur within those reactions...
In part two we tested on how the surface area of a substance changes the reaction rate of solutions..
It took the whole class... But we continue on with the lab tomorrow...
The End. =D
The next scribe is... gear321.
We did part one and part two
In part one we tested the reactiblilty of certain substances in different solutions... And the time that it took for reactions to occur within those reactions...
In part two we tested on how the surface area of a substance changes the reaction rate of solutions..
It took the whole class... But we continue on with the lab tomorrow...
The End. =D
The next scribe is... gear321.
Monday, April 2, 2007
First day back from spring break
Today, our lovely chemistry teacher handed out our fire works assignments AND our tests. i hope you guys all passed with flying colors. anyways we went on reviewing the kinetics assignment that was given to us on friday of last last week. after than we were given a textbook assignment that's due on wednesday or thursday. oh and a wordsearch for fun. that is all the next scribe is ree-shard
Subscribe to:
Posts (Atom)
