Exam Study Guide
IPS
Safety Notes
For Every Lab
- Goggles must be kept OVER YOUR EYES until Mr. Leeds says to put them away.
** even if you are already finished and cleaned up **
- Report ALL accidents/spills to Mr. Leeds immediately
- Try your best to use common sense
In Case of Emergency
Safety Equipment in Classroom
Chemicals
- Never Taste Chemicals (even if they look yummy!)
- Always WAFT liquids to detect odor
- NEVER WAFT SOLIDS/ POWDERS
- Avoid touching chemicals
- Always wash hands with soap and water after lab
- If chemicals touch skin: flush skin with water for 1 minute AND notify Mr. Leeds
Glass
- Hot and cold glass look the same
- Never used chipped or broken glass
-tell Mr Leeds and dispose of broken glass in proper trash
- Never use force to insert or remove glass
Alcohol Burners
- Roll up sleeves, put UP long hair, NOT just pull back (or u cannot do lab)
- Never walk away from a lit burner
- Never point the open end of a hot test tube at yourself or someone else
- Do not look down into a test tube/ beaker while it is being heated
- Make sure burner is capped and flame is out when done
End of Experiment
- CLEAN UP AREA & MATERIALS COMPLETELY !!! (or you lose points)
- Make certain that burner is out if one was used
- Keep goggles on (over eyes) until Mr. Leeds says to put them away
Pre Lab- Reaction in a Bag
Purpose
Lab Safety
2. Wear apron
Data:
Solid A
- white
- not powdery
- white chunks
- hard
- flaky
- looks like broken shells
Solid B
- white
- powdery
- looks like baking soda
- small clumps together
- thinner than sand
Red Liquid
- no odor
- looks like colored water
Extra Pre Lab Notes
- delta- change
- A + liquid = hot temperature
- B + liquid = cold temperature
- AB + liquid = gas
- hot temperature- exothermic reaction
- cold temperature- endothermic reaction
Experimental Errors
- hole in the bag- would not know that a gas was produced
Post Lab- Reaction in a Bag
Red Liquid
- Phenol Red
- used as a ph indicator
- below 7 turns yellow
- above 8 turns pink
Ph Scale
- measures acidity
- goes from 0-14
- 0-7= acid
- 7= neutral
- 7-14= alkaline/ basic
- lemon juice- 1.5
- tums- 10
Solid A
- calcium chloride (calcium + chlorine)
- preserver
- acidic: about 6
- hydrotropic- attracted to water (absorbs water)
- USES:
- Canned veggies- keeps them from getting mushy
- electrolyte in sports drinks
- flavors pickles- salty, preserves them
Solid B
- sodium bicarbonate (baking soda)
- not acidic: about 8.4
- USES:
- baking
- laundry detergent
- toothpaste
- kitty litter
Pre Lab- Heating Baking Soda
Purpose
Blue Dot Questions
- What do you observe at the bottom of the test tube?
- What do you observe near the top of the test tube?
- What do you observe in the inverted bottle?
- Where do you think the gas came from?
- Where did the droplets on the test tube come from?
- Describe the color of the liquid in each test tube?
- Are the two white powders the same substance? What is your evidence.
Blue Dot Answers
- Nothing major is happening, but the baking soda does become a little clumpy.
- Condensation, moisture, foggy
- Gas from the baking soda pushes the water out of the bottle
- Gas comes from heated baking soda.
- Comes from the hot gas touching a cooler surface- gas turns back into a liquid
- The heated test tube is darker and cloudier than the non heated.
- No, because the heated is not the same color as the non heated which we know is 100% baking soda.
Lab Safety
- Roll up sleeves, put UP long hair, NOT just pull back (or u cannot do lab)
- Never walk away from a lit burner
- Never point the open end of a hot test tube at yourself or someone else
- Do not look down into a test tube/ beaker while it is being heated
- Make sure burner is capped and flame is out when done
Experimental Errors
- hole in the tubing- won't see the bottle fill with gas and water won't push out of the bottle
- stopper is not snug in test tube (same result at #1)
- Stirring rod not cleaned before you begin- contaminate the test tubes (color may not change)
Post Lab- Heating Baking Soda
Terms
- Control group- unheated (didn't do anything to it)
- Experimental group- heated (flame lit, temp. changed, burned baking soda- loose control)
- indicator- tea (indicated that heated baking soda has changed because the color of the tea changed)
- variable- something you try to measure
A) independent- causes a change in the dependent variable (temperature)
B) dependent- color of tea
C) Control Factors- factors we control during the lab
- same type of tea
- same amount of baking soda
- same amount of tea
- same stirring time
- same size test tube
Extra Question
- less, ( or equal to) because the condensation comes from the baking soda being heated and the baking soda cannot produce more than itself.
Box Question #1
- because baking soda when heated produces a gas which helps batter/ dough to rise
Volume Notes 1.2
Volume of Solids
- unit of measurement- cm^3 (cubic centimeters)
- volume- LxWxH
- standard unit of length- meter (m)
- 1 centimeter (1cm)= 0.1m
- unit cube- a small cube 1cm on each edge
- one cubic centimeter- 1cm^3
Volume of Liquids
- use a graduated cylinder to measure volume
- ALWAYS CHECK THE INTERVALS OR SCALE
- units- milimeters (mL) or cm^3
- 1mL= 1cm^3
- read from bottom of meniscus
Box Questions 3-8
4. Rectangular box A has a greater volume than rectangular box b but the length of box a is less than the length of box b. How is this possible?
5. Adding a stone to a graduated cylinder containing 25.0 cm^3 of water raises the water level in the cylinder to the 32.0 cm^3 mark. What is the volume of the stone?
6. A student has a large number of cubes that measure 1cm along each edge.
- how many cubes will be needed to build a cube that measures 2 cm along each edge
- How many cubes will be needed to build a cube that measures 3 cm along each edge
- what is the volume, in cubic centimeters, of each of the cubes in a and b?
7. One rectangular box is 30 cm long 15 cm wide and 10 cm deep. A second rectangular box is 25 cm long 16 cm wide and 15 cm deep. Which box has the larger volume?
8. Look in book for diagram.
Box Question Answers 3-8
4. the width and heigh in box a are greater than box b
5. 7cm^3 (rock displaces the water)
6. A: 8 cubes
B: 27 cubes
C: 8cm^3, 27cm^3
7. Box b
8. As the surface increases the depth decreases.
Reading Scales 1.3
Single Pan Balance Notes
- check that pan is clean and dry
- always "zero" balance before EACH massing
- push all riders to zero
- use adjustment knob if needed
3. Never switch pans
4. pick up balance by red bar only
5. don't zero balance when done
Box Questions 9-13
12. Three students reported the length of a pencil to be 12 cm, 12.0 cm, and 12.00 cm. What number could they have rounded up from and down from to get to each answer.
13. What advantage is there to making a graduated cylinder narrow and tall rather than short and wide?
Box Question Answers 9-13
B. 1.61 cm, 2.52 cm, 4.50 cm
C. because it is more accurate
10. A. 0.1 cm^3
B. 0.2 cm^3
11. A. 4.0 cm^3
B. 1.30 cm^3
12. 12cm: 11.5-12.4
12.0cm: 11.95- 12.94
12.00cm: 11.995- 12.994
13. Because the lines are further apart because less surface= more depth and easier to read
Measurement Lab
Divisions of Graduated Cylinders
2. 25mL- 0.5 cm^3
3. 50mL- 1 cm^3
4. 100mL- 1 cm^3
Length
Mass
Binder Clip- 8.541 g
Big Stopper- 12.00 g
Small Stopper- 8.400 g
Pre Lab- 1.4 Measuring Volume by Displacement of Water
Volume of dry sand- 30cm3
Volume of water- 17cm3
Volume of sand and water- 35cm3
Volume of sand alone- 18cm3
Volume of airspace- 12cm3
Fraction of sand that is air- 0.40
Percent of sand that is air- 40%
v. sand and water- v. water= sand alone
v. dry sand air- v. sand alone= air space
air/dry sand= fraction of sand that is air
*sand alone has no air space
Post Lab- Measuring Volume by Displacement of Water
1. sand sticks to sides of wet cylinder- v. of sand and water would be too low
2. pour water into sand- water sits on top of the sand because the air spaces don't allow water to filter down.
Extra Question
1. why were lab groups instructs to use different amounts of sand?
- it didn't matter how much dry sand you had, the amount of air space was approximately 40%
Box Questions 14-17
14. The volume of a marble is 1.0 cm3. of the following choices, which tells how many identical marbles are needed to full an empty graduated cylinder to the 100cm3 mark?
- c- less than 100
15.
A-
Volume of dry sand- 50cm3
Volume of water- 30cm3
Volume of sand and water- 60cm3
Volume of sand alone- 30cm3
Volume of airspace- 20cm3
Fraction of sand that is air- 0.40
Percent of sand that is air- 40%
B- What is the volume of water that does not fill air spaces between the sand particles?
- 20cm3 (airspace)
E- What fraction of the total volume of dry sand is sand particles?
- 60% (sand alone/ dry sand)
1.6 Mass Notes
- earliest balance found in Egypt approximately 7,000 years old
Mass- standard unit is grams (g)
1 kilogram= 1,000 g
1kg= 2.2 pounds
Box Questions 18-21
18. suppose two objects with different shapes were hung from opposite ends of an equal arm balance. The bar remained horizontal. Which of the following statements about the properties of the objects are true?
- B- the masses of the objects are the same
19.
Elevator- count, mass
Stadium- count
Bridge- mass
Bus- count
Water tank- volume
Train Car- count
Theater- count
Saucepan- volume
21. What is your mass in kilograms
- your weight/2.2
Pre Lab- 1.8 The Sensitivity of the Balance
M. of a single square- M. of 20x20/ 400
ending mass (#10)- initial mass of stopper= ∆M
∆M/# of yes's= sensitivity
Box Questions # 23, 26 27 (look in lab book for charts)
27. *you can tell if someone made a mistake if not all of the numbers are within the sensitivity of the balance.
Post Lab- 1.8 The Sensitivity of the Balance
Sensitivity of the Balance- the lightest mass that you can expect the balance to detect, plus or minus the margin of error when you mass something.
Experimental Error
1. cut out wrong amount of groups of squares
2. graphite on 20x20
Box Questions #29-37
29. Suppose the volume of a piece of glass is measured by displacement of water of burner fuel. How would the two measurements compare?
- they would be the same
30. In determining the volume of a rectangular box, five cubes were found to fit exactly along one edge, and four cubes to fit exactly along another edge. However, after six horizontal layers had been stacked in a box, a space at the top was left unfilled.
A- if the heigh of the space was half the length of an edge of a cube, what was the volume of the box?
- 5x4x6.5= 130cm3
B- If the height of the space was 0.23 of the length of an edge of a cube, what was the volume of the box?
- 5x4x6.23= 124.6cm3
31. look at picture in the book- 4x2x3= 24 cubes
34. Fuel oil is sold by the gallon, gas for cooking by the cubic foot, and coal by the ton. What are the advantages of selling the first two by volume and the last by mass?
- fuel oil and gas are liquids so they are much easier to sell by volume. Too many steps to sell by mass. Sell coal by mass so you don't have to pay for air space.
36.
A- What is the volume of the aluminum cube with edges that are 10cm long?
- 10x10x10= 1,000 cm3
B- What is the mass of the aluminum cube? (One cubic centimeter of aluminum has a mass of 2.7g)
- 1,000x2.7= 2700g
37. One cubic centimeter of gold has a mass of 19g. What is the mass of a gold bar 1.0x2.0x25?
- 50x19= 950g
Exam Study Guide
Exam Study Guide
Chapter 1 Test
Part A: Calculations
1. In a rectangular box the following measurements were found: six cubes fit exactly along one edge, and five cubes fit exactly along another edge. However after seven horizontal layers had been tacked in the box, a space at the tope was left unfilled.
If the height of the space was half the length of an edge of a unit cube, what was the volume of the box?
- lxwxh 6x5x7.5= 225
If the height of the space was 0.47 of the length of an edge of a unit cube, what was the volume of the box?
- lxwxh 6x5x7.47 = 224.1
2. What is the mass of an iron bar that is 2cm x 4cm x 11cm? (1cm3 of iron has a mass of 7.8g)
- 1/7.8= 8/x= 686.4
3. A volume of 87cm3 of dry sad is added to 46cm3 of water for a total volume of 104 cm3.
Volume of Dry Sand- 87
Volume of Water- 46
Volume of Sand & Water- 104
Volume of Sand Alone- 53
Volume of Air Space- 29
% of Dry Sand that is Sand- 67%
% of Dry Sand that is Air Space- 33%
a. What is the volume of water than fills the air spaces in the dry sand?
- 29cm3
b. What is the volume of water that does not fill the air spaces in the sand?
- 17cm3
4. To stay physically fit, Mr. Leeds is constantly training. He weighs a trim 178 lbs. What is his weight in kilograms?
- 178/2.2 = 81kg
5. Use the following data to find the sensitivity of the balance used
Group Change Mass
1 yes 14.32
2 yes 14.33
3 yes 14.34
4 no 14.34
5 yes 14.35
6 no 14.35
7 yes 14.36
8 no 14.36
9 no 14.36
10 yes 14.39
∆M/# of yes’s 0.09/6 = 0.015
14.39-14.30 = 6
Sensitivity of the balance: 0.02
6. Five IPS scholars use the same single-pan balance of mass their friend’s ring. None knew the results of the others their results are listed in the table below:
Student
Mass (g)
1) 3.752
2) 3.755
3) 3.715
4) 3.756
5) 3.760
Did any of the students make a mistake in their massing’s?
Yes because the range is 0.045 which is bigger than the sensitivity of the balance 0.01-0.02.
Part B: Lab Experiments:
1. During the Heated Baking Soda Experiment a lab group does not realize that they have a hole in their rubber tubing. How will this affect their understating of the lab?
- This will affect their understanding of the lab because the gas will escape from the tubing and it will never reach the bottle. The water in the bottle would not come out because the gas didn’t reach it. So they would not know that a gas would come out. They would not get the proper outcome.
2. During the Reaction in a Bag Experiment a lab group does not realize that there is a hole in their zip lock bag. How will this affect their understanding of the lab?
- This will affect their understanding of the lab because the gas would escape and the bag wouldn’t inflate with gas.
3. For the Measuring Volume by Displacement of Water Experiment Mr. Leeds assigned lab group’s different amounts of dry sand to begin the lab. Why did he do this?
- He did this because no matter what amount of dry sand you were given, the amount of air space in the sand was approximately 40%.
Part D: Critical Thinking
In the sensitivity of a balance lab you were instructed to add 10 groups of squares with a mass between 0.003g and 0.007g to an already massed stopper. Why did they choose this range of mass for your 10 groups of squares and not a smaller range?
- They chose this range of mass for your 10 groups of squares and not a smaller range because your ten groups of squares would only be composed of 1 or 2 squares in them. The balance would not be able to detect a change in mass because it is too light. This would have changes your lab because your sensitivity of the balance would be different because your changes in mass wouldn’t have a lot so #10- initial mass of the stopper would give you a very small number, the two numbers would not be far from each other.
Chapter 2
The Mass of Dissolved Salt
Histograms
The Mass of Ice and Water
The Mass of Copper and Sulfur
The Mass of a Gas
Conservation of Mass Notes
Chapter 2 Test
1.Describe a possible error discussed in class, which could lead to a loss in mass during the Mass of a Gas lab.
- Error: If you do not put the cap on quick enough after the Mi.
- Explanation: You will lose mass because some of the gas will escape, so when you mass it after the solution your mass will be too low.
2. Describe a possible error discussed in class, which could lead to a loss in mass during the Mass of Copper and Sulfur lab.
- Error: if there is a hole in the rubber tubing during the heating.
- Explanation: This would cause a loss in mass because the yellow smoke, which is a gas will escape do you will lose mass. Your mass after the heating would be incorrect.
3. During the experiment of Ice and Water again in mass is noted by a lab group give a possible error (specific to the lab), discussed in class, as to how this gain in mass could have occurred. Be sure to explain why this error would cause a gain in mass.
- This will cause a gain in mass because the condensation adds mass. ADDS TO MF AND IT WASN’T THERE DURING THE MI.
4. You are working in a class with no air conditioning, it is 90 degrees. You lab is to take the mass of the water that is 65 degrees in a small plastic bottle with a cap on, then place the bottle in a walk in freezer allowing the liquid to solidify, then re-mas the bottle while in the freezer. What is a possible error you should be aware of.
- Condensation may form on the outside of the bottle during the Mi and then freeze
Chapter 3
Mass and Volume/ Density
The Density of a Solid/ The Density of a Liquid
The Density of a Gas/ The Range of Densities
Chapter 3 Test
1. During the Density of a Gas Lab the rubber tubing is incorrectly inserted near the bottom (mouth) of the bottle.
- Less gas to collect in the bottle
2. If the error in #3 is made it will have the following affect:
- Volume decrease, density increase
3. In the Density of a Gas lab a student forgets to include the foil for the Mf, the result is:
- Mass of gas increase, density increases