IPS Exam Study Guide
all tests and quizes
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
Nurse: ext: 2828
Safety Equipment in the Room
- 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
- hot glass and cold glass look the same
- never use chipped or broken glass
- tell Mr. Leeds and dispose of broken glass in proper trash
- never use force to remove or insert glass
- roll up sleeves, put UP long hair, NOT just pull back (or you 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 AND 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
Chemicals used in the lab
Red Liquid
*ph measures the acidity of a substance
- ph scale goes from 0-14
- 0 is acidic and 14 is alkaline
- below 7 turns yellow and above 8 turns pink
Solid B
uses:
- baking
- laundry detergent
- toothpaste
Solid A
uses:
- canned vegetables
- electrolyte in sports drinks
- flavors pickles
what the lab (reaction of the lab) should look similar to
experimental errors
additional information to know
- solid A and the red liquid (calcium chloride and phenol red) makes a hot reaction which is also known as an exothermic reaction
- Solid b and a liquid (sodium bicarbonate and phenol red) makes a cold reaction which is also known as an endothermic reaction
Heating Baking Soda Lab
Purpose
How the Lab Works
experimental errors
- hole in the tubing: gas would be released and you would not know that a gas was produced because no water will be pushed out of the bottle
- stirring rod not cleaned before you begin because it will contaminate the substances
Important Additional Information to Know
- What do you observe near the top of the test tube? It is fogging and condensing.
- What is happening in the inverted bottle? The water is leaving the inverted bottle and going into the big plastic container. Basically, the gas enters the inverted bottle forcing the water out.
- Where do you think the gas comes from? The gas comes from the heated baking soda.
- Where did the droplets on the test tube come from? When the heated gas is coming from the baking soda, it is very hot and when it touches the cooler surface of the test tube, it turns back into a liquid.
- Are the two white powders the same substance? No, the heated tube is different because it is not the same color as the unheated test tube which we are 100% sure is simply baking soda and tea. (we know this because nothing was done to the test tube or nothing extra was put into the mixture)
- Is the amount of baking soda at the bottom of the test tube more or less than the amount of condensation formed at the test tube? Less/equal because the condensation comes from the baking soda and the baking soda is not capable of producing more than itself.
- the tea in the heated test tube will usually be darker than the tea in the unheated test tube
- Why do you think baking soda is used in baking? When heated, the baking soda releases a gas that helps dough/batter to rise
terms in the heating baking soda lab
- control group: unheated test tube
- experimental group: heated test tube
- indicator: tea because it indicates/shows that the heated baking soda has changed
- independent variable: causes a change in the dependent variable- in this lab:the temperature (heat)
- dependent variable: color of the tea
- control factors: same type of tea, same amount of baking soda, same amount of tea, same stirring time, same size test tube
Volume
- unit of measurement cm3 (cubic centimeters)
- volume= LxWxH
- standard unit of length is m (meter)
Unit cube
Volume of liquids:
- use a graduated cylinder to measure volume
- always the intervals or scale units= milliliters (mL) or cm3
- 1 mL= 1cm3
- read from bottom of meniscus
Reading Scales
- check that pan is clean and dry before usage
- always zero balance BEFORE each massing (push all riders to zero and use adjustment knobs if needed)
- What advantage is there to making graduated cylinders narrow and tall rather than short and wide? The lines are further apart because there is less surface which equals more depth which makes it easier to read
First Test- Chapter one (not including quiz material)
Measuring Volume by Displacement of Water lab
Purpose:
How the Lab Works
Important Data Tables to know how to do
Volume of dry sand
32 cm3
Volume of water
16 cm3
Volume of sand and water
35.5 cm3
Volume of sand alone
19.5 cm3
Volume of air space
12.5 cm3
Fraction of sand that is air (read to 0.01)
0.39 -12.5/32 (air over dry sand)
Percent of sand that is air
39%
volume of sand and water - volume of water = sand alone
To find air space:
volume of dry sand - volume of sand alone = volume of air space
extra question/blue dot questions
It did not matter how much sand you started with, the amount of air was approximately 40%
experimental errors
- when pouring the sand into the cylinder with water, the sand sticks to the sides of the wet cylinder
- if you accidentally pour the water into the sand instead of pouring the sand into the water (water sits on top of sand because the air doesn't allow the water to filter down)
extra information to know
1. find the volume of a weight (rock, etc.)
2. use displacement of water method with weight and cork
3. subtract the volume of the weight
4. calculate the volume of the cork
SUGAR DISSOLVES IN WATER
Mass notes
SEE PAGE 15 IN TEXTBOOK
- beqa- ancient standard mass used in egypt (unit of measurement)
- earliest balance found
- from egypt
- approximately 7,000 years old
1 kilogram= 1000 grams
1 kilogram= 2.2 pounds
to find your weight in kilograms- take your weight and divide by 2.2
Sensitivity of a balance
purpose
data tables to know
∆M
0.073
Number of yes’s
3
Sensitivity
0.0243
to get change in mass- ending mass minus initial mass of stopper
then number of yes's
to get sensitivity of the balance- change in mass divided by the number of yes's
experimental errors
- if there were marks on the graph paper from a pen, pencil or other ink/led, it adds mass to the paper and the calculations will be off
- if the squares that are cut out are 10 groups of the squares that are between .003 and .007, and they are not exactly the same length and width because the cutting was off, then one of the squares could have a larger mass than another
Additional information to know
- how can you tell students made an incorrect error when you are given masses of an object? find the range (biggest number minus smallest), and then see if they are in the range of the sensitivity of the balance
sensitivity of the balance post lab
- before 1982- 95% copper and 5% zinc
- after 1982- 2.5% copper and 97.5% zinc because copper become more expensive so it costed less to do this
- during 1943- they were made of steel and zinc because copper was needed for shell casings (bullets)
- a 1943 copper penny has sold for over $82,500!
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
class sensitivities
0.1 0.1 0.1 0.2 0.1 0.2 0.1 0.2 0.1 0.2
Chapter 2
the mass of dissolved salt
purpose
experimental errors
2. if the outside of the bottle is wet during the mass initial
3. not drying off the cap because water in mass initial will not be there for mass final
4. remove the cap before mass final because that will cause spillage or leakage
5. not shaking long enough because it will not dissolve
6. cap not on tightly because that will cause spillage or leakage
7. spill salt when pouring into bottle
ALL LEAD TO A DECREASE IN THE MF WHICH IS NOT GOOD
extra info to know
You will get the wrong symbol which is a different change in mass
2. do you need to know the individual masses of the samples of water and salt to determine the change in mass when the two samples are mixed?
No, because the amount of water should be the same for MI and MF
3. how would you be able to get the dissolved salt back? how do you think its mass would compare with the mass of dry salt you started with?
you would let the water evaporate and the masses would be the same
histograms
- type of graph (similar to bar graph)
- graphs used for financial, sports, weather etc.
- when graphing, find largest and smallest number you must graph first so you know your range
HISTOGRAM RULE-
if data falls on a line, it is graphed in column to the right
the mass of ice and water lab
purpose
important data tables to know
Mass of bottle/cap (g)
5.360
5.414
Mass of bottle/cap/ice (g)
6.114
5.710
MI of ice (g)
0.754
0.296
Mass of bottle/cap/water (g)
6.081
5.705
MF of water (g)
0.721
0.291
Change in Mass (g)
-0.033
-0.005
TO FIND MASS FINAL OF WATER- BOTTLE/CAP/WATER- BOTTLE/CAP
TO FIND MASS INITIAL OF ICE- BOTTLE/CAP/ICE-BOTTLE/CAP
post lab
- comes from warm water vapor in the air (humidity) when it touches cool surface of bottle it turns from gas to liquid
experimental errors
- not wiping off condensation because you'll get a gain in mass
- bottle is wet during mass initial because you'll loose mass
- shaking bottle because you will loose mass because water could leak out
purpose
what the reaction looks like
data
Mass of test tube,sheet,band
34.131g
MI of test tube, sheet, band, copper, sulfur unheated
37.131g
MI of copper and sulfur
3g
Mass of test tube, sheet, band, copper, sulfur heated
37.113g
MF of copper and sulfur
2.982g
Change in mass
-0.018g
post lab and extra info to know
- melting point of copper: 1,100 degrees celsius/ 2,000 degrees Fahrenheit
- melting point of sulfur: 112 degrees celsius/ 235 degrees fahrenheit
- yellow smoke- water in sulfur turns to vapor (gas) and rises in test tube (the sulfur has water because it is hydro-tropic)
- when the yellow smoke cools: sulfur bonds with the copper and forms copper sulfide
Why do we use the rubber sheet instead of maybe a piece of paper?
it is stretchy and the stopper would pop off or the test tube would crack
experimental errors
1. hole in the rubber sheet- the gas escapes
2.the rubber sheet pops off- gas escapes
3. the rubber band isn't on tight enough- gas escapes
ALL LEAD TO GAS ESCAPING AND A LOSS OF MASS
to find the percentage change in mass of the reacting substances- change in mass over mi equals x over 100
2.6 mass of a gas
purpose
data
Bottle/cap/tablet/ water (MI)
26.380 g
28.149 g
28.690 g
Bottle/cap/solution (MF)
26.380 g
28.105 g
28.690 g
Change in Mass
0 g
-0.044 g
0 g
Mass after gas is released
26.250 g
27.959 g
28.659 g
Mass of the gas
0.13 g
0.146 g
0.03 g
way the lab works
post- lab
1. water in the pan during the MI- loose mass
2. the cap is not tight or not on quick enough- loosing mass
2.7 conservation of mass notes
the law of conservation of mass- in a closed system, mass will remain constant, regardless of hte actions of the processes inside the closed system
Chapter 3
characteristic properties
- property of an object: does not tell you what the substance is made out of ex. shiny, sharp
- property of a substance: this helps you to identify what the object is made out of ex. wooden, tar
3.2 mass and volume
how the lab works
data
1st long cylinder
2.651 g
1.01 cm3
2nd long cylinder
2.679 g
0.99 cm3
3rd long cylinder
2.645 g
1.00 cm3
Small aluminum cylinder
2.846 g
1.00 cm3
Brass cylinder
8.471 g
1.00 cm3
post lab
- can the brass cylinder have the same mass and volume as a piece of aluminum? no, the volume would change because you'd have to change the shape
experimental errors:
- cylinder could be wet during massing- mass increases because there is extra water
- water splashes out of your cylinder- volume goes down
mass and volume notes
- objects that are made of the same substance that have the same volume, will have the same mass regardless of their shape
- mass of an object will double, if its volume doubles
- objects that have the same volume but are made of different substances will not have the same mass
3.3 density
3.5 the density of a solid
to utilize density to determine if 3 metal objects are made of the same substance
post lab
- the histogram shows that cube 1 and slab are most likely the same substances and cube 2 is a different substance
- density of water = 1 g/cm3
- if something has a density below the density of water, it will float
- the rock is sedimentary. all of the groups have different densities because the rock is formed by many substances being compressed together. different substances = different densities
experimental errors
- paint chipped off the object- loose mass
- find volume of rock before mass- density increases
3.6 density of a liquid
to use density to compose 2 liquids to determine if they are the same substances
post lab
- outside of the cylinder is wet- adds mass
liquid a- magnesium sulfate- epsom salt
3.7 density of a gas
to produce and collect a gas in order to accurately determine the density of the gas
******scientific notation - left- positive; right- negative
post lab
- Why is it important to hold your hand over the mouth of the bottle wile removing it from the water? the water will leave the bottle because it has a greater density than air
- gas from the lab was carbon dioxide which has a density of 1.8 x 10-3 g/cm3
- does the density of a gas depend on how much gas you collect? No, density depends on the substance
- what happens if the gas you collected dissolves in your water? the volume goes down and density goes up (tubing must be at top of the bottle due to gas dissolving)
- 1 kilogram = 1,000 grams
- 1 meter= 100 cm
experimental errors
- if you don't put foil on during the mf- mf goes down and change in mass becomes too big and density goes up
- if there's an air bubble- volume goes down and density goes up
CHAPTER ONE TEST
Part A: Calculations
- If the height of the space was half the length of an edge of a unit cube, what was the volume of the box?
answer- 6 x 5 x 7.5= 225 cm3
why: L x W x H (7.5 because the length of a unit cube is 1 cm and half of that is 0.5. You had to add 0.5 to the height because the space at the top was half the length of an edge of a unit cube.)
-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?
answer- 6 x 5 x 7.47= 224.1 cm3
why- L x W x H (7.47 because the height of the missing space was 0.47 of the length
of an edge of a unit cube so you had to add that to the height given)
2. what is the mass of an iron bar that is 2 cm x 4 cm x 11 cm (1 cm3 of iron has a mass of 7.8g)
answer- 2 x 4 x 11 x 7.8= 686.4 g
3. a volume of 87 cm3 of dry sand is added to 46 cm3 for a total volume of 104 cm3.
volume of dry sand- 87 cm3
volume of water- 46 cm3
volume of sand and water- 104 cm3
volume of sand alone- 58 cm3 (sand and water minus water)
volume of air space- 29 cm3 (dry sand minus sand alone)
% of dry sand that is sand- 67%
% of dry sand that is air space- 34%
what is the volume of water that fills the air spaces in the dry sand?
answer- 29 cm3
why- the answer is volume of air space
what is the volume of water that does not fill the air spaces in the sand?
answer- 17 cm3
why- water minus air
4. to stay physically fit, Mr. Leeds is constantly training. He weighs 178 lbs. what is his weight in kilograms?
answer- 81 kilograms
why- 178 divided by 2.2 because 1 kilogram equals 2.2 pounds
use the following data to find the sensitivity of the balance:
initial mass of stopper- 14.30 g
group 1- change- mass 14.32
group 2- change- mass 14.33
group 3- change- mass 14.34
group 4- no change- mass 14.34
group 5- change- mass 14.35
group 6- no change- mass 14. 35
group 7- change- mass 14.36
group 8- no change- mass 14.36
group 9- no change- mass 14.36
group 10- change- mass 14.39
sensitivity of the balance= 0.02 g
why- change in mass: 0.09 (final minus initial)
number of yes': 6
sensitivity: 0.015
**** How do you know when someone has made a mistake in their massing when seeing a data table?
answer- you find the range and see if it is near the number of the sensitivity of the balance.
part B: Lab experiments
During the hating baking soda lab, a group does not realize that they have a hole in their rubber tubing. How will this affect their understanding of the lab?
The group will not realize that a gas was produced by the baking soda because it will escape through the hole. Also, the gas that does reach the inverted bottle, will not be enough to push out the water form the bottle making it hard to testify that a gas was produced.
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?
The group will not realize that a gas may have been produced from their mixture with the substances because it will escape through the hole.
For the Measuring Volume by displacement of water lab Mr. leeds assigned lab groups different amounts of dry sand to begin the lab. Why did he do this?
He assigned different amounts of dry sand to show that it didn't matter how much sand you started with because the percent of dry sand that is air space will be approximately 40%
Part C: Measurement
- 3 cups flour- volume
- 1 tablespoon baking powder- volume
- 1 1 pound can of pumpkin- mass
- 1/2 teaspoon vanilla- volume
- cinnamon to taste- other
- 1/2 cup milk- volume
for the following objets tell whether you would use a volume measurement, mass measurement, or count to describe the capacity of the object.
- auditorium- count
- bridge- mass
- saucepan- volume
- water tank- volume
(for next measuring problems see box questions in lab notebook)
Part D: Critical Thinking
Those numbers were chosen because you could expect to actually see a change in the mass when gradually adding on more squares. Also, 0.01-0.02g is about the sensitivity of the balance so it probably would detect the mass, but maybe not each time. The lightness of it might also cause more margin for error.
CHAPTER TWO TEST
Part I: Laboratory Experiments
Error- if the cap is not on tight enough or quick enough there will be a loss in mass.
Explanation-There will be a lose in mass because the gas could escape and we wouldn't know because gas is invisible
2. Describe a possible error discussed in class, which would lead to a loss in mass during the mass of copper and sulfur lab. be sure to explain why this error would cause a loss in mass.
error- if the sheet has a hole there will be a loss in mass
explanation- the gas that is created could escape and therefore wouldn't be there in the mass after the heating.
3. During an experiment of ice and water a gain in mass is noted by a lab group. Give a possible error, 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.
Error: if there is condensation on the outside of the bottle there will be a gain in mass
Explanation: the condensation wasn't there during the MI, so if it is there during the MF there will be a gain in mass because the condensation doesn't come from the ice. The condensation comes from warm water vapor in the air that touches the cooler surface of the bottle and turns form a gas to a liquid.
Part II: Analysis
A) put the cap on, wipe off the condensation on the outside and continue
B)not worry because the condensation on the outside and inside should balance out
C) Start the lab over
D) wipe off equal amounts of condensation inside and outside, put on cap and continue
In all four experiments from chapter 2 the common theme involved investigating changes in mass of different states of matter. You now know that in all the labs there should be no change in mass because:
A)in all 4 labs everyone in class calculated no change in mass
B) all the labs followed einstein's theory of relativity
C) Newton's laws of motion
D) law of conservation of mass
You are working in a class with no air conditioning, it is 90 degrees fahrenheit. your lab is to take the mass of water (that is 65 degrees fahrenheit ) 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-mass the bottle while in the freezer. What is a possible error you should be aware of:
A) condensation may form on the inside of the bottle during the Mi and then freeze
B) the water could start boiling and push the cap off
C) condensation may form on the outside of the bottle during the Mi and then freeze
D) all of the above
A lab group dissolves 2g of slat into 8 cm3 of water in a beaker with no cover. After a few days all of the water has evaporated. What will remain in their beaker?
A) 2g of salt
B) 4 cm3 of water
C) 1g of salt
D) none of the above
Part III: Calculation
change in mass over M i= x over 100
CHAPTER THREE TEST 3.1-3.8
Part B: Laboratory Experiments
A) we didn't have enough small beakers
B) it is the most accurate method
C) we did not have to transfer liquid
D) all of the above
E) Both B & C
F) none of the above
When finding the density of a liquid the most accurate thing to do is:
A) find the volume first and then pour it into a beaker for massing
B) Find the mass first and then pour it into a graduated cylinder
C) either A or B
D) none of the above
during the density of a gas lab the rubber tubing is incorrectly inserted near the bottom (mouth) of the bottle. This will cause:
A) more water to be pushed out of the bottle
B) less gas to collect in the bottle
C) more water to fill up the test tube
D) less gas will leave the test tube
if the error in #3 is made it will have the following affect:
A) volume increases, density decreases
B) mass increases, density increases
C) volume decreases, density increases
D) mass decreases, density decreases
when calculating the density of a rock (an irregular shape) it would be an experimental error to
A) mass the rock prior to finding its volume
B) waft the rock
C) find the volume prior to massing
D) none of the above
when the alka seltzer tablet is mixed with water, sodium bicarbonate within the tablet releases
A) hydrogen
B) nitrous oxide
C) baking soda
D) carbon dioxide
in the density of a gas lab a student forgets to include the foil for the Mf, the result
is:
A) mass of gas increases, density increases
B) mass of gas increases, density decreases
C) mass of gas decreases, density increases
D) mass of gas decreases, density decreases
Epsom salt is the marketing name for which chemical compound:
Magnesium sulfate
CHAPTER 3 QUIZ
questions I got wrong
If a group finds the volume before the mass the rock is wet.
What did the histogram make you aware of about the three objects in the density of solid lab?
cube 1 and slab had similar densities and cube 2 was a different substance
during the density of a gas lab the rubber tubing is incorrectly inserted near the bottom (mouth) of the bottle. This will cause:
the mass would increase. therefore, the mass goes up and so does the density