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.
Showing posts with label Tucker. Show all posts
Showing posts with label Tucker. Show all posts
Thursday, March 3, 2011
Wednesday, February 2, 2011
Extra Stoich Practice!!
For a problem that gives moles of Substance A and asks for mols of substance B use 1 step. For this one step you will just use the balanced equation ratios.
For a problem that gives moles of Substance A and asks for grams of substance B use 2 steps. Start with the balanced equation ratios for the first step and then use the molar mass (from periodic table in grams/mole) of substance B for the second.
For a problem that gives grams of Substance A and asks for mols of substance B use 2 steps. Start with the moalr mass of substance A and then use the bal. eq. ratios.
For a problem that gives grams of Substance A and asks for grams of substance B use 3 steps. Start with the molar mass of substance A, then use bal. eq. ratios, and then finish off with the molar mass of substance B.
For a problem that gives ml of Substance A and asks for grams of substance B use 4 steps. Start with the DENSITY, then use moalr mass of substance A, then bal. eq. raitos, then finish off with the molar mass of substance B. If you are ever given the grams and asked for ml, just reverse this order.
Now try to identify how many steps the following problems contain and what the steps involve (no need for any math, X and Z just hypothetical substances, just set problems up!!)
1. How many moles of X react wirh 25.0g of Z?
2. How many grams of Z will be produced from 12.35g of X?
3. How many ml of Z can be produced if we also produced 35.245g of X?
4. How many moles of Z can react with 500.0moles of X?
5. What mass of Z would be needed to produce 10.1moles of X?
BONUS: How many atoms of X can be produced from 25g of Z? Use mol island for this one
For a problem that gives moles of Substance A and asks for grams of substance B use 2 steps. Start with the balanced equation ratios for the first step and then use the molar mass (from periodic table in grams/mole) of substance B for the second.
For a problem that gives grams of Substance A and asks for mols of substance B use 2 steps. Start with the moalr mass of substance A and then use the bal. eq. ratios.
For a problem that gives grams of Substance A and asks for grams of substance B use 3 steps. Start with the molar mass of substance A, then use bal. eq. ratios, and then finish off with the molar mass of substance B.
For a problem that gives ml of Substance A and asks for grams of substance B use 4 steps. Start with the DENSITY, then use moalr mass of substance A, then bal. eq. raitos, then finish off with the molar mass of substance B. If you are ever given the grams and asked for ml, just reverse this order.
Now try to identify how many steps the following problems contain and what the steps involve (no need for any math, X and Z just hypothetical substances, just set problems up!!)
1. How many moles of X react wirh 25.0g of Z?
2. How many grams of Z will be produced from 12.35g of X?
3. How many ml of Z can be produced if we also produced 35.245g of X?
4. How many moles of Z can react with 500.0moles of X?
5. What mass of Z would be needed to produce 10.1moles of X?
BONUS: How many atoms of X can be produced from 25g of Z? Use mol island for this one
Monday, January 24, 2011
M-1/24-Stoichiometry
1. We picked up four sheets in class today (Mol Notes- 1page, and Pair,Dozen, Mol Lab Activity- 3pages)
Mr. Tucker mentioned that second semester involves a bit more problem solving and that if we do not stick with the 10-15min a night we might fall behind.....MAKE SURE TO PERFORM NIGHTLY ASSIGNMENTS!!!!
2. We then talked about the mole concept and filled out one page of notes:
* A pair is 2 of something
A dozen is 12 of something
A mole is 6.02 x 1023 of something (this is useful for counting particles/atoms/molecules)
*A mole is then equal to this number above as well as ____g/mol as found on the periodic table
(for instance, 1 mole of Carbon is 12.01g/1mole and 1 mole of Aluminum is 26.98g/1mole)
* the ratios are then 1mol/6.02 x 1023 or 1mol/___g (we can use these as conversion factors)
* We then filled out a mole island conversion chart. This helps to know when to use the conversion factors in mole problems.
3. We then performed the Pair, a Dozen, A Mole Activity
*again, a pair is 3 of something, a dozen is 12 of something, and a mole is 6.02 x 1023 of something
* we did a few calculations together:
2.5moles of donuts x 6.02 x 1023 donuts = 1.505 x 1024 donuts
1mole donuts
* Next, we looked at a big chunk of Aluminum foil. It was 26.98g of it. This means that we also had 1 mole of it (because this is the molar mass found on the periodic table for Aluminum) and also that we had 6.02 x 1023atoms of Aluminum (since 1 mole of something is always 6.02 x 1023 of that thing)
*Finally, we poured 18ml of water in a graduated cylinder (since water has a density of 1g/ml this means that we also had 18g of water in the graduated cylinder). When we looked at the periodic table (H=1g/mole and O=16g/mol, and water has a formula of H2O) we figured out that 1 mole of water will have a mass of 18g/mol. This means that in the graduated cylinder we also had 1mol of water!!!! It really wasn't that exciting, but Mr. Tucker seemed to think so, so hence the exclamation points. Then, since we had 1mole fo water in the graduated cylinder we must also have 6.02 x 1023 water molecules in the cylinder as well!!!
HOMEWORK:
* Meet in the science lab tomorrow
* Transfer the mol island chart from our notes to the small notecard....we should use this when performing mole problems till we get the hang of it
Mr. Tucker mentioned that second semester involves a bit more problem solving and that if we do not stick with the 10-15min a night we might fall behind.....MAKE SURE TO PERFORM NIGHTLY ASSIGNMENTS!!!!
2. We then talked about the mole concept and filled out one page of notes:
* A pair is 2 of something
A dozen is 12 of something
A mole is 6.02 x 1023 of something (this is useful for counting particles/atoms/molecules)
*A mole is then equal to this number above as well as ____g/mol as found on the periodic table
(for instance, 1 mole of Carbon is 12.01g/1mole and 1 mole of Aluminum is 26.98g/1mole)
* the ratios are then 1mol/6.02 x 1023 or 1mol/___g (we can use these as conversion factors)
* We then filled out a mole island conversion chart. This helps to know when to use the conversion factors in mole problems.
3. We then performed the Pair, a Dozen, A Mole Activity
*again, a pair is 3 of something, a dozen is 12 of something, and a mole is 6.02 x 1023 of something
* we did a few calculations together:
2.
1
* Next, we looked at a big chunk of Aluminum foil. It was 26.98g of it. This means that we also had 1 mole of it (because this is the molar mass found on the periodic table for Aluminum) and also that we had 6.02 x 1023atoms of Aluminum (since 1 mole of something is always 6.02 x 1023 of that thing)
*Finally, we poured 18ml of water in a graduated cylinder (since water has a density of 1g/ml this means that we also had 18g of water in the graduated cylinder). When we looked at the periodic table (H=1g/mole and O=16g/mol, and water has a formula of H2O) we figured out that 1 mole of water will have a mass of 18g/mol. This means that in the graduated cylinder we also had 1mol of water!!!! It really wasn't that exciting, but Mr. Tucker seemed to think so, so hence the exclamation points. Then, since we had 1mole fo water in the graduated cylinder we must also have 6.02 x 1023 water molecules in the cylinder as well!!!
HOMEWORK:
* Meet in the science lab tomorrow
* Transfer the mol island chart from our notes to the small notecard....we should use this when performing mole problems till we get the hang of it
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