Chapters 1-3 Study Guide
By Alec Simonson
Lab Safety
- 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 to Mr. Leeds immediately.
- Try to use your best common sense.
In Case of Emergency:
- Nurse: ext: 2828
Safety equipment in classroom:
- Fire extinguisher
- Fire blanket
- Eye wash/shower
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 for one minute AND notify Mr. Leeds.
Glass:
- Hot glass and cold glass look the same.
- Never use broken or chipped glass.
- Never use force to remove and 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 hot 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 is used.
- Keep goggles on (over eyes) until Mr. Leeds says to put them away.
Chapter 1
Reaction in a Bag
Post Lab: Reaction in a Bag
- Used as a pH indicator
- pH scale:
- measure acidity
- goes from 0-14
- Acidic-Neutral-Alkaline
- Lemon juice: 1.5
- Tums: 10
Two Solids:
Solid A:
- Calcium Chloride (calcium + chloride)
- acidic
- hydrotropic: absorbs water (attracted to water)
- Uses:
- canned vegetables: keeps them from getting mushy
- electrolytes in sports drinks
- flavor pickes (salty flavor)
Solid B:
- Sodium Bicarbonate (baking soda)
- hydrotropic
- non-acidic
- Uses:
- Cupcakes, cookies (baking)
- toothpaste
- laundry detergent
Heating Baking Soda
Post Lab: Heating Baking Soda
- Control group: unheated baking soda and tea.
- Experimental group: heated baking soda and tea
- Indicator: Tea (shows us that the substances were different)
- Variables: a category you try to measure.
- Independent variable: cause a change in the dependent variable. Ex: temperature (heat).
- Dependent variable: tea color (was dependent on temperature).
- Control factors:
- Same type of tea.
- Same amount of baking soda.
- Same amount of tea.
- Same size test tube.
Experimental Errors:
- Hole in the tubing->won't see gas fill the bottle.
- Stopper not snug.
- Not cleaning stirring rod->contaminate
Box Question #1 Page 5:
- Why do you think baking soda is used in baking?
When heated, it releases a gas. it helps the batter (dough) rise. Ex: bread, cookies, cupcakes.
1.2 Volume Notes
- Unit of measurment: cm^3 (cubic centimeters)
- Volume L*W*H (A*B*C)
- Standard unit of length: meter (m)
- 1 centimeter (1cm)= .01m
- 100cm=1m
- Unit cube->a small cube that is 1cm on each side (1*1*1)
- one cubic centimeter: 1cm^3
Volume of Liquids
- Use a graduated cylinder to measure volume.
- 1mL=1cm^3
3. 50cm^3
4. The width and height are greater on box A.
5. 7cm^3.
6. a. 8
b. 27
c. (a. 8cm^3)(b. 27cm^3)
7. The second rectangular box.
8. They are equally spaced because as the surface increases, the depth increases.
Single Pan Balance Notes
- Check that the pan is always clean and dry.
- Always "zero" before each massing.
- Pull all riders to zero (left).
- Use adjustment knob if needed.
- Never switch pans.
- Pick up balance by red bar only.
- Don't zero balance when done.
9. a. 1.2-1.3cm and 3.7-3.8cm
b. 1.64cm, 2.53cm, 4.5cm
c. Because the measurement will be more accurate and because ruler B does have millimeters and ruler A does not.
10.(a) 0.1 and (b) 0.2
11.4.0cm^3 and 1.3cm^3
12.a. 12cm: 11.5-12.4cm
b. 12.0cm: 11.95-12.04cm
c. 12.000cm: 11.995-12.004cm
13. Lines are further apart because more depth due to lack of surface.
-easier to read
Measurement Lab
Divisions of various graduated cylinders:
- 10mL: 0.20
- 25mL: 0.50
- 50mL: 1.0
- 100mL: 1.0
Mass:
The masses of various objects:
- Nickel: Mass: 4.950g
- Binder Clip: Mass: 8.690g
- Big Stopper: Mass: 12.140g
- Small Stopper: Mass: 8.030g
Measuring Volume By The Displacement of Water
Experimental Errors
2. If you pour the water into the sand. Water sits on the top of the sand because the air spaces don't allow for water to filter down)
Extra Question
It doesn't matter how much dry sand you begin with. All groups have approximately 40%.
Box Questions #14-17
15. See the chart below.
a. Fill up a beaker with a liquid that doesn't let sugar dissolve (non water-based liquid)
b. Record volume.
c. Add sugar.
d. Record new volume and calculate.
17.
a. Find the volume of a weight (Rock, etc.)
b. Fill cylinder to a known amount.
c. Use weight to submerge cork.
d. Record the new volume.
e. Subtract the volume of the weight to find the volume of the cork.
1.6 Mass Notes
- Beqa: ancient standard mass used in Egypt.
- Earliest balance in Egypt (approximately 7,000 years old)
- Mass: stabdard unit g(grams).
- 1 kilogram = 1,000 grams
- 1 kilogram = 2.2 pounds (lbs).
Box Questions #18-21
19.
a) count, mass
b) count
c) mass
d) count
e) volume
f) mass/volume
g) count
h) volume
20. See chart below.
your weight/2.2
1.8: Sensitiviy of a Balance Lab
Box Questions #23,26,27
26.
average: 21.418333333...
27.
a. No because they are all within 0.014 of each other.
b. No I do not think there is anything wrong with the balance because all measurements are within the sensitivity of the balance.
c. Take the average of all five numbers.
Post Lab
Before 1982:
- 95% Copper
- 5% Zinc
After 1982:
- 2.5% Copper
- 97.5% Zinc
1943: made of steel and zinc
- copper was needed for shell casings (bullets)
- A 1943 copper penny has sold for $82,500.
Sensitivity of the Balance:
- The lightest mass that you can expect the balance to detect.
- Also the margin of error when you mass something.
Review Questions #24-31, 34-37
30.
a. 5 X 4 X 6.5 = 130 cubes
b. 5 X 4 X 6.23 = 124.6 cubes
31. 24cm^3
34.
Fuel/Gas (liquid): By volume because it is safer and there are less steps involved.
Coal (solid): By mass because it has air spaces in between the pieces of coal.
35.See chart below.
a.10 X 10 X 10 = 1000 cm^3
b. 1cm^3 = 2.7g
2.7 X 1000
2,700g
37.
a. 1.0 X 2.0 X 25 = 50 cm^3
b. 950 g.
Chapter 2
2.1: The Mass of Dissolved Salt Post Lab
- Not drying off the cap.
- Remove cap before the Mf which would cause spillage and leakage.
- If you did not shake the salt long enough.
- If the cap is not on tight enough which would cause spillage and leakage.
- If you spill some salt while pouring it into the bottle.
Box Questions #1-6 p. 29
2. Because you would not know the the answer was positive or negative.
3. No, because they are dependent on the ΔM.
4. I could get it back by letting the salt evaporate. The mass would remain the same.
5. No, too small, much less than the sensitivity of a balance.
6.
a. +1kg, -2kg
b. +4⁰C, -5⁰C
Histogram Rule
- If what you are graphing falls on a line, you put it in the column to the right.
- Interval: going from one line to the next line.
- If a number is in an interval, it is between two lines.
- By moving where the zero starts, it will change how the graph looks.
Box Questions #8-11
a. yes
b. yes
c. yes
d. yes
e. no
f. no
9.
a. -0.01 to -0.03 is the interval.
b. 5, 7, 10, 14
10.
a. 0-.02
b. 3,4,6,8,9,16,17,18,19
c. 2,20
11.
a. See histogram
c. Our graph is not better because unlike figure 2.3, our histogram did not condier the sensitivity of the balance.
2.4: The Mass of Ice and Water Post Lab
- After you melt the ice, condensation shows up on the outside of the bottle which adds to the mass and the Mf and affects the outcome of the lab.
Comes from warm water vapor in the air (Humidity). When it touches the cool surface of the bottle, it turns from a gas to a liquid.
More Errors:
- Not wiping up condensation which adds mass.
- Shaking the bottle which would cause water to leak out.
- Bottle is wet during the Mi which is going to cause a loss in mass.
- The ice is not completely melted for the Mf.
- Remove the cap either during the Mi or the Mf which would cause a loss in mass.
2.5: Mass of Copper and Sulfur Post Lab
- Melting point of copper almost 1,100 degrees celcius (2,000⁰F)
- Melting point of sulfur: 112 degrees Celsius, 235 degrees Fahrenheit.
- How to find Celsius: Subtract by 32 and Divide by 1.8.
Smoke: Yellow Smoke
- Water that was in the sulfur turns into a water vapor (gas) and rises in a test tube.
- When it cools, the sulfur liquid bonds to the copper and forms copper sulphite.
Experimental Errors:
- Cleaning the pan between the Mi and the Mf which would cause a loss in mass.
- A hole in the rubber sheet which would cause the gas to escape.
- If the reaction was not complete.
- If sulfur stuck to the sides of the test tube (does not react)
- If the rubber sheet was not sealed on the test tube which would cause gas to escape.
Box Questions #15-16 p. 38
a. 2.956
b. Mi= 2.956
Mf= 2.902
c. ΔM/Mi=1.890
16.
a. Yes
b. Repeat lab, look at class data.
2.6: Mass of a Gas Post Lab
Experimental Errors:
- Ring of water in the pan after the Mi which would cause a loss in mass.
- Is the cap is wet and the alka seltzer reacts during the Mi which would cause a loss in Mass.
- If the cap is not on tight enough or not closed quickly which would cause the gas to escape which would cause a loss in mass.
- If you touch the tablet after the Mi which would cause a loss in Mass.
Alka-Seltzer:
Aspirine, citric acid, and sodium bicarbonate
pain flavor (baking soda)
(vitamin C) (gas and anti-acid)
2.7 Conservation of Mass
- closed system: a space where nothing can enter or leave.
- Law of Conservation of Mass: In a closed system mass will remain constant, regardless of the actions of the processes inside the closed system.
Box Questions p. 41, #17; p. 42 #19-23
19. It depends on the enviornment.
- On a planet (somewhere with gravity), yes.
- No gravity, then no.
20. This is a law of nature because of the mixture of gas molecules and other etc. in the atmposphere.
Review Questions #21-23; p. 42
21.
a. Some water vapor could escape.
b. Condensation could form on the inside of the bottle.
22. Yes it would as long as it is a closed system.
23. It would stay the same because it is a closed system.
Chapter 3
Chapter 3 Vocabulary
- Characteristic Properties- Properties that show differences between
substances. Examples: density, boiling point, solubility,
melting point.
- Plateau- The flat portion of a graph. Indicates no change in the
dependent variable (y-axis.)
- Phase Diagram- A graph that shows the changes in state of matter for
any substance. Represents physical changes in the
substance.
- Barometer- Used to measure atmospheric air pressure. Contains a
column of mercury and a metric scale in a sealed container.
- Barometric Pressure- air pressure generated by the atmosphere.
Density- Mass per unit volume of any substance. Unit of measure is
g/cm3.
Characteristic Properities
property of a substance: this helps you identify what the object is made out of
Box Questions p. 44 #2
b. object, object, object, substance
c. object, object, substance, object
3.2: Mass and Volume Post Lab
2. It would be 2 times the mass.
3. It would be 2 times the volume.
4. 2g
Experimental Errors:
- The cylinder is wet which would add mass.
- Mix up the long cylinders which would mean the masses and the volumes are all the same.
Mass and Volume Notes
- Objects that are made out of the same substance that will have the same volume, will have the same mass.
- The mass of an object will double if its volume doubles.
- Objects that have the same volume but are made out of different substances will not have the same mass.
Box Questions #3-5; p.46
4. A
5. B
Density
Box Questions 6,7,8; pgs. 47-48
a. Yes, more vehicles, more wheels.
b. No, because the number of wheels on each vehicle will not change.
c. Yes, because vehicles are categorized by the number of wheels.
3.5: The Density of a Solid Post Lab
- Paint chipping off of an object which would cause a loss in mass.
- Finding the volume of the rock before finding the mass.
- Measuring the same side of an object twice.
Box Questions #13-17; p.51
a. Clean and zero balance.
b. Measure the length, width, and height of the block with a ruler
c. Mass the block
d. Divide M/V to get the density
16. Yes the volume has to be the same so the density will be the same.
17. No because different amounts of limestone would have different masses and the equations for the volume of a cone and the volume of a cube are different.
3.6: The Density of a Liquid Post Lab
- Not rinsing the cylinder between substances.
- Does not remass the second cylinder (2nd liquid)
- If the outside of the graduated cylinder is wet during the first mass (empty)
magnesium sulfate: Epsom Salt
- one liquid (liquid A) had a lot dissolved into it (greater density)
- another liquid (liquid B) had not as much magnesium sulfate dissolved into it (lesser density).
Box Question #18; p. 52
a. different liquids
b. same liquids
3.7: The Density of a Gas Post Lab
- Spilling water when measuring the volume of the bottle.
- Not putting the foil back on the pan.
- Too big of an air bubble.
- Break tablet after Mi (touching).
Blue Dot Answers:
2. Water represents what did not get pushed out by the gas.
3. ΔM is negative because the gas has left the tablet.
The Gas is Carbon Dioxide.
Box Questions #19,21,22; p.54
21.No, the density of this gas is too small.
22.
a. the volume of the gas would be less
b. the density would be larger
Extra Question
Box Questions #23-27; pg. 56
a. gas
b. solid
c. liquid/solid
d. liquid/solid
e. gas
24. 1kg=1000g
V= 1111.1cm^3
25. copper 178g, iron 156g
26.
a. 39.5g/cm^3
b. 50g/cm^3
27. 39.88g