EXAM STUDY GUIDE
Taylor Jane McKee
IPS Lab Safety Notes
- 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
- Nurse: ext: 2828
Safety equipment in classroom
- fire extinguisher
- fire blanket
- eye wash/shower
Chemicals
- never taste chemicals
- 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 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
Alcohol Burners
- 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 sapped and flame is out when done
End of Experiment
- CLEAN-UP AREA & MATERIALS COMPLETELY!!!! (Or you LOSE points)
- make certain that burner is out of one was used
- keep goggles on (over eyes) until Mr. Leeds says to put them away
Volume Notes
volume= LxWxH
standard unit of length=meter (m)
1 centimeter (1cm)= 0.01m
100
100cm= 1m
Volume of Liquids
-use a graduated cylinder to measure volume
*Always check the intervals or scale
units= mil liters (mL) OR cm3
1mL=1cm3
-read from bottom of meniscus
Single Pan Balance Notes
- check that pan is clean and dry
- always "zero" balance before EACH massing
*push all riders to zero (left)
*use adjustment knob if needed
3. Never switch pan
4. Pick up balance by red bar only
5. don't zero balance when done
Lab: React in a Bag
B + liquid = cold (Endothermic Reaction= takes it away)
A + B + liquid = gas
Red Liquid or Phenol Red
- used as a pH indicator
- below 7 turns yellow
- above 8 turns pink
Solid A
- calcium chloride (calcium + chlorine)
-mildly acidic
- hydrotropic: attracted to water (absorbs water)
USES:
- canned vegetables (keeps them from getting mushy)
- electrolyte in sport drinks
- flavored pickles
Solid B
- sodium bicarbonate (baking soda)
- hot acidic
USES:
- baking
- cat litter
- toothpaste
- laundry detergent
Lab: Heating Baking Soda
control group: unheated test tube
experimental group: heated test tube
indicator: tea (showed you that that heated test tube wasn't baking soda)
variables: something you want to measure
independent variable: causes a change in the dependent variable
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
Box Questions
It releases gas when heated, which helps dough/batter to rise.
3. How many cubic centimeters of water are required to fill a graduated cylinder to the 500.0-mL mark?
50 cm3
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?
Box A has more space then box B.
5. Adding a stone to a graduated cylinder containing 25.0 cm3 of water raises the water level in the cylinder to the 32.0 cm3 mark. What is the volume of the stone?
7 cm3
6. a. how many 1 cm cubes will be needed to build a cube that measures 2 cm along each edge?
8 cubes
b. How many 1 cm cubes will be needed to build a cube that measures 3 cm along each edge?
27 cubes
c. what is te volume, in cubic centimeters, of each of the cubes in a and b?
8 cm3 + 27 cm3
7. One rectangular box is 30 cm long, 15 cm wind, 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?
The second rectangular box
8. figure A shoes a cone-sharped graduate used for measuring the volume of liquids. Why are the divisions not equally spaced?
As the surface increases the depth decreases
Test #1
If the height of the space was half the length of an edge of a unit cube, what was the volume of the box?
6x5x7.5= 225 cubes
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?
6x5x7.47= 224.1 cm3
What is the mass of an iron bar that is 2cm x 4cm x 11cm? (1cm3 of iron has a mass of 7.8)
1cm3/88cm3=7.8/x x= 686.4g you get 88 by 2 x 4 x 11
Part B: Lab Experiments:
1. During the Heating Baking Expiration a lab group does not realize that they have a hole in their rubber tubing. How will this affect their understanding of the lab?
thye do not know that baking soda produces a gas when heated.
2. During the Reaction in a lab group does not realize that there is a hole in the zip lock bag. How will this affect their understanding of the lab?
not know how the reaction produces a gas.
3. For the Measuring Volume by Displacement of Water Experiment Mr. Leeds assigned lab groups differetn amounts of dry sand to being the lab. Why did he do this?
A group gets approz 40% air space no matter what they start with.
4. In the sensitivity of a balance lab you were instructed to add 10 groups of squares with a mass between .003g and .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; for example: .001g and .003? How would this have change your lab?
The mass would be too small for balance to defect. There would be no change in mass.
Test # 2
- start the lab over
2. 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:
- Law on conservation of mass
3. You are working in a lcass with no air conditioning, it is 90 degrees F. Your lab is to take the mass of water (that is 65 degrees C) 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 greezer. What is a possible error you should be aware of:
-condensation may form on the inside of the bottle during the Mi and then freeze
4. A lab group dissolves 2g of salt into 8cm3 of water in a beaker with no cover. After a few days all of the water has evaporated. What will remain in their beaker?
- 2g of salt
Test #3
-it is the most accurate method
- we did not have to transfer liquid
3. During the Density of a Gas lab thee rubber tubing is incorrectly inserted near the bottom of the bottle. This will cause...
- less gas to collect in the bottle
4. If the error in #3 is made it will have the following affect:
-volume decrease, density increase
5. When calculating the density of a rock (irregular shape) it would be an experimental error to...
- find the volume prior to massing
6. When the alka seltzer is mixed with water, sodium bicarbonate within the tablet resales:
- carbon dioxide
7. In the Density of a Gas lab a student forgets to include the foil for the Mf, the result is:
- mass of gas increases, density increases
8. Epsom salt is the marketing name for which chemical compound:
Mag. sulfide