IPS Exam Study Guide

CHAPTER 1

Lab Safety

For Every Lab:

Goggles must be kept ON YOUR FACE until Mr. Leeds says to put them away.

Report ALL accidents/spills to Mr. Leeds immediately.

Always 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 (even if they look yummy!).

Always WAFT liquids to detect odor.

NEWER WAFT SOLIDS/POWDERS!

Avoid touching chemicals.

Always wash hands with soap and water after lab.

**Flush skin with water if contact with chemicals occurs** AND notify Mr. Leeds.

Glass:

Hot glass and cold glass look the same.

Never use chipped or broken glass.

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.

Diluting Acid:

Acid must be added to water.

Never add water to acid.

-Could cause an exothermic reaction.

-Water is less dense (lighter) than acid so it will sit on top of acid and could splash out.

End of Experiment:

Make sure burner is capped and flame is out.

CLEAN-UP AREA & MATERIALS COMPLETELY!!!!! (Or you LOSE points.)


Scientific Method

How to solve a problem

1. Identify problem.

2. Gather information.

3. Form hypothesis/theory.

4. Perform experiment.

5. Analyze data.

6. Conclusion.

Reaction in a Bag Post-Lab

Heat:

The combination of Solid A and either water or the red liquid make it feel hot.

Cold:

The combination of Solid B and either liquid make it feel cold.

Gas:

The combination of Solid A & B with either liquid cause the gas to form. The red liquid isn't necessary, because Solid A, B, and water creates the gas.

Liquid:

A liquid needs to be there for the reaction to occur, because the combination of Solid A & B doesn't react.

Yellow Color:

The absence of the yellow liquid in the experiments after the first is because the yellow color needs to have Solid A, B, and the red liquid.

Chapter 1 Vocab

Observation- information obtained by the senses, often by direct measurement

Inference- a conclusion based upon known observations

Hypothesis- a proposed solution to a scientific problem

Control Group- the group that is the standard for comparison in any experiment

Experimental Group- the group receiving the variable being tested

Control Factors- the variables that are held constant. They are the same for both the control group and the experimental group.

Indicator- a substance used to show the presence of another substance

Volume- the amount of space something occupies. True of solids, liquids, and gases.

Volume Displacement Technique- quick and easy way to determine the volume of a solid or gas.

Mass- the amount of matter in a substance. True of solids liquids and gases.

Meniscus- the curved portion of a liquid when in a container. Must read the bottom of the meniscus, at eye level, for proper measurement

Baking Soda Post Lab

The top of the test tube is much cooler than the bottom so when the hot gas from the baking soda touches the cooler surface, it turns back into a liquid.


If the heated test tube was still baking soda, it would be the same color as the unheated.


Control Group: unheated baking soda/tea

Experimental Group: heated baking soda/tea

Indicator: tea

Control Factor: amount of baking soda; amount of time heated; amount of teal size of test tubes; type of tea; stirring time


Experimental Errors:

Should affect outcome/ results

-hole in the tubing, which could cause water level to stay the same in the bottle and container

-cap burner before remove tubing, which could cause a vacuum tubing

-stopper not on right, which could cause condensation and mess up bottle/container reaction

-stirring rod contamination


Volume Notes

Unit of measurement: cubic centimeter (cm3)

Volume: l x w x h (a x b x c)

Standard unit of length: meter (m)

1 centimeter (1 cm) = 0.1 m

100 cm= 1 m

Centi=100


Unit Cube:

-a small cube on each edge

one cubic centimeter


Volume of Liquids:

-use a graduated cylinder to measure volume

*Always check the intervals of scale

-units: milliliters (mL) or cm3

*1 ml = 1 cm3


Volume of Rock:

  1. Fill cylinder to a known amount - enough to cover object.
  2. Record the water level
  3. Put rock in cylinder
  4. Measure the liquid level
  5. Subtract original water level from rock level

-Original Level: 70.0 ml

-New Level: 73.1 ml

-Rock Volume: 3.1 ml

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 pans

4. Pick up balance by red bar only

5. Return riders to zero when done

Post Lab - Sand

Experimental Errors:

-sand sticks to sides of cylinder

  • volume of sand and water will be less

-pours water into sand

  • volume of sand and water rises and water sits on sand

-reads sand level, not water level

  • volume of sand and water is less

-pour sand too fast

  • the funnel overflow

-sand sticks to funnel (because of dampness)

  • measurements are less


Extra Question:

-It didn't matter how much sand you began with, the percent of air space within the sand is about 40%.

Post Lab- Sensitivity/Pennies

Pennies

-Before 1982: 95% Copper; 5% Zinc

-After 1982: 2.5% Copper; 97.5% Zinc

**In 1943, pennies were zinc plated steel


Sensitivity:

Change in mass ÷ Number of yes of changes in mass = Sensitivity

Usually- 0.02

Balance's Sensitivity: The margin of error of the balance when you mass an object.


Experimental Errors:

  • not zeroing the balance
  • cutting unevenly
  • read balance incorrectly
  • pencil marks on paper
  • not estimating to proper place

CHAPTER 2

Chapter 2 Vocab

Histogram- a bar graph that shows the number of times a value is represented for a large sampling group

Conservation of Mass- In all changes, mass is exactly conserved, provided nothing is added or allowed to escape. Must be a closed system! NOT true for volume.

Laws of Universe- Guessed generalizations based on many experiments. Can be adjusted when necessary to account for any changes in the limitation of a law

Post Lab- Salt

Consider the Sensitivity of the Balance

  • looking at the change in mass and plus or minus .02

Experimental Errors

-all lead to a decrease in maass

  • salt spills from cap into bottle
  • not drying cap
  • clean pan between Mi and Mf
  • cap not tight so water spills out
  • not shaking long enough
  • bottle is wet on outside during Mi

Histogram

Histogram Rule: If data falls on a line, you graph it in the column to the right.

Post Lab: Ice

Condensation:

Comes from warm water vapor touching cold surface of bottle. It changes from a gas to a liquid


Errors:

  • not wiping off condensation on outside
  • ice isn't fully melted
  • shaking bottle
  • cap not tight which causes evaporation
  • not drying bottle and cap
  • remove cap before Mf

Post Lab: Copper/Sulfur

Errors:

  • shaking test tube
  • capping flame before reaction ends
  • rubber sheet not on tightly
  • hole in rubber sheet
  • clean pan between massing

Post Lab: Alka Seltzer

Errors:

  • too much water
  • cap isn't on tight enough/fast enough
  • bottle wet on outside during Mi
  • cap wet


Alka Seltzer:

  • made of sodium bicarbonate, aspirin, citric acid
  • baking soda (sodium bicarbonate) releases gas

Conservation of Mass Notes

Law of Conservation of Mass:

  • In a closed system, mass will remain constant regardless of the actions of the processes inside the closed system

CHAPTER 3

Chapter 3 Vocab

Characteristic Properties: properties that show differences between substances. Ex: 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 substances. Unit of measure is g/cm3

3.1 Notes

Property of Object: describes the object itself

Property of Substance: identify what the object is made of

Post Lab: Aluminum/Brass

Errors:

  • cylinder is wet when massing (increase)
  • re-mass cylinder
  • not enough water in cylinder
  • water splashes out (less volume)


Extra Question:

-The mass of all aluminum cylinders should be 2.700 g/cm3 (plus or minus .02).

Mass and Volume Notes

  1. Objects that are made of the same substance that have the same volume, will have the same mass, regardless of their shape.
  2. The mass of an object will double if its volume doubles.
  3. Objects that have the same volume, but are made of different substances will NOT have the same mass.

Density Notes

Mass/Volume=Density

units: g/cm3 (grams per cm3)

Density of Solids Post Lab

The Rock:

-All have different densities because the rock is formed by many substances being compressed together. Different substances = different densities


Errors:

-measure Vi of rock before massing

  • mass will increase because water is on rock during massing so the density will increase

-measure same side of cube/slab

-mix up the cubes

-measure from end of ruler, not zero

  • volume lowers so density will increase


Density of Liquids Post Lab

Errors:

-liquid sticks to inside walls of cylinder so increase in mass and increase in density

-contaminated cylinder (wet on inside)

-dry out cylinder AFTER it's massed while empty


Magnesium Sulfate= Epsom Salt (what was put in liquid)


Liquids were water but liquid A had more Epsom Salt (higher density)


Blue Dot:

Neither way is more accurate. (graduated cylinder and then mass or vice versa)

Density of a Gas Post Lab

Blue Dot:

  1. Water will leak out of bottle.
  2. The mass of the volume displaced is the same volume as the gas.
  3. Subtract Mi from Mf to find mass of gas.
  4. Mass is lost because the gas leaves the tablet and goes to the bottle.


Errors:

-hand doesn't seal bottle so water leaks out

  • volume increase so density decrease

-remove stopper before tubing so classroom air goes in

  • volume increase so density decrease

-put tubing in, then tablet, then stopper (order) so classroom air goes in

  • volume increase so density decrease

-forget to include foil in Mf

  • Mass increase so density increase

-touch/break tablet after Mi so dust leaves tablet after Mi

  • change in mass increase so density increase

-stopper not tight/ hole in tubing/ too long getting tubing into bottle/ tubing being too low in bottle (gas dissolves in water) so gas escapes

  • volume decrease so density increase


Gas comes from sodium bicarbonate (baking soda) in alka seltzer

-Gas is carbon dioxide (1.8 x 10-3)