IPS Exam Study Guide

chapters 1-3

Scientific Method Notes

1. Identify the problem

2. Gather information

3. Form Hypothesis

4. Preform experiment

5. Analyze Data

6. Form conclusion

Chapter 1 vocabulary

Observation-information obtained by the senses- often by direct measurements

Inference-a conclusion based upon known observations

Hypothesis-a proposed solution to a scientific observation

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 variable that are held constant. they are the same for both the control group and experimental group.

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

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

Volume of Displacement-Quick and Easy way to determine the volume of a solid or gas

Mass-the amount of matter in a substance (true for solids, liquids, 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

Chapter 2 vocabulary

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

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

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

Experimental Errors Lab: Heating Baking Soda

1. hole in rubber tubing

2. Stopper not on tight

-can't see the gas pushing out the water from inside the bottle

3. Cap on burner before removing tubing

Experimental Errors Lab: Measuring Volume by Displacement of Water

1. Sand stick to side of wet cylinder

-volume of sand and water will be lower

2. Record sand level not water level

-volume of sand and water will be lower

3. Sand gets stuck in the funnel

volume of sand and water will be lower

4. Pour sand too fast

-overflows funnel

Experimental Errors Lab: The Mass of Dissolved Salt

-cleaning pan b/w Mi +Mf.

-spilling the salt from cap to bottle

-remove the cap before Mf

-Not shaking salt long enough

-Cap not on tight (water will spill out)

-Not drying cap (starts dissolving)

-Bottle is wet on the outside during Mi.

1. Most of these errors lead to a decrease in mass

Experimental Errors Lab: The Mass of Ice and Water

1. Not wiping off the condensation

2. Ice isn't melted all the way

3. shaking the bottle (water would leak out)

4. not drying bottle before massing the 1st time

5. open cap before you final mass

-water could splash out

-water evaporate

Experimental Errors Lab: The Mass of Copper and Sulfur

1. Shake test tube

-sulfur stuck to sides

2. hole in the rubber sheet

-gas escapes/loss in mass

3. sheet not on tightly

-gas escapes/loss in mass

*spilling sulfur while putting it in the test tube is NOT an error

* use a sheet instead of a stopper because the sheet is flexible and stretches

Experimental Errors Lab: The Mass of a Gas

1. cap not on tight enough

2. not drying outside of the bottle before Mi

3. inside cap is not dry

-affects the change in mass

1. removing cap

2. water splashes out when loosening cap

-affects the mass of gas

Law of Conservation of Mass

*in a closed system mass will remain constant, regardless of the actions of the processes inside the closed system

-exception: mass is always conserved, however, in a nuclear reaction some mass is lost. The energy released in a nuclear reaction will be absorbed into surrounding material, adding mass to it. So, the mass is not really "lost"

Experimental Errors Lab: Mass of Volume

1. switch cylinder when massing so you would re mass the same cylinder.

2. if you don't wipe off water before massing cylinder.

-Adds mass

3. switching bags from the 1st day to the second day

4. not enough water in the graduated cylinder

5. water splashes out of graduated cylinder so the volume would be different

3.2 Notes

-if you want the masses to be the same you would have to change the volume

-the mass of an object will double if it's volume doubles

-objects that are made of the same substance, that have same volume, will have the same mass.

-objects that have the same volume but are made of different substances will NOT have the same mass

3.5 Notes

- if two objects have the same volume, the object with the LARGER mass will have a greater density

-the rock: all senementary rocks have different densities because the rock is formed by many substances being compressed together. Different substances = different masses

Experimental Errors Lab: The Density of Solids

1. Mix up the cubes

2. Measure same side of cube or slab twice

3. Measure from the very beginning of the ruler

-the volume will be smaller, so the density will be smaller

3.6 The Density of Liquids

1. dry cylinder

2. cylinder contaminated (wet on inside)

3. liquid sticks to the inside wall of cylinder

4. Dry out cylinder AFTER it's massed

-Mass would be increased/ Density increases

3.6 Notes

-Magnesium sulfate= Epsom salt (liquids)

-we waft liquids to show we can't depend on smell to find what the substances are


Experimental Errors Lab: Density of a Gas

1. hand not tight on the bottle so some water leaks (after reaction)

-volume bigger/ overall density lower

2. Touch the tablet after Mi

-bigger mass/ larger density

3. Hole in tubing/ to slow putting tubing in bottle/ stopper not on tight enough

4. Air bubble in the bottle

-volume decreases/ overall density goes up

3.7 Notes

-gas in lab is Carbon Dioxide/ comes from sodium bicarbonate

- if you don't hold your hand on bottle while taking it out, water could leak out of the bottle

-the left over water in the bottle is the volume of the gas.