EXAM STUDY GUIDE

Taylor Jane McKee

IPS Lab 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


  • Nurse: ext: 2828



Safety equipment in classroom


  1. fire extinguisher
  2. fire blanket
  3. 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

unit of measurement= cm3 (cubic centimeters)

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

  1. check that pan is clean and dry
  2. 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

A + liquid = hot (Exothermic Reaction= out/heat)

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:

  1. canned vegetables (keeps them from getting mushy)
  2. electrolyte in sport drinks
  3. flavored pickles


Solid B

  • sodium bicarbonate (baking soda)
  • hot acidic


USES:

  1. baking
  2. cat litter
  3. toothpaste
  4. laundry detergent

Lab: Heating Baking Soda

Terms


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:

  1. same type of tea
  2. same amount of baking soda
  3. same amount of tea
  4. same stirring time
  5. same size test tube


Box Questions

1. Why do you think baking soda is used in baking?

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

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 stacked in the box, a space at the top 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?

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

1. during the ice and water lab a lab group forgot to put the cap on their bottle. By the time they realized their mistake some condensation had already formed on the outside and inside of the bottle. They should:

- 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

1. In order to calculate density, we found both the mass and volume of the liquid in hte graduated cylinder because...


-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