Exam Study Guide
By: Emily Smith
- goggles over eyes until directed to take them off (even if finished)
- report all accidents/ spills to Mr. Leeds immediately
- try to use common sense
Safety equipment in classroom:
- fire extinguisher
- fire blanket
- eye wash/ shower
- never taste
- never touch
- always waft liquids
- never waft solids/ powders
- wash hands with soap and water after lab
- if chemicals on skin: flush skin with water for a minute and tell Mr. Leeds
- hot and cold glass look the same
- never use chipped/ broken glass (tell mr. leeds and dispose correctly)
- never use force to insert or remove glass
- roll up sleeves; tie up hair
- never walk away from lit burner
- never point open end of test tube at yourself or someone else
- don't look down into heated beaker/ test tube
- make sure burner is capped and flame is out when done
End of Experiment:
- clean up area and materials (or points lost)
- make sure burner is out
- keep goggles on eyes until otherwise directed
volume of sand alone: sand/water- water
volume of air space: dry sand- sand alone
volume of water that fills the air spaces in the dry sand: airspace
volume of water that does not fill the air spaces in the sand: volume of water- airspace
1kg: 2.2 pounds
sensitivity of balance: end-beg.=change in mass/#'s of y's
volume: cubic centimeters
percentage change in mass of the reacting substances: change in mass/ Mass initial= x/100
standard unit of length: meter
1 centimeter: 0.01 meter
1mL: 1cubic centimeter
change in mass/ #of y's= sensitivity
density= g/cubic centimeters
less gas in bottle: volume decrease> density increase
foil not included in Mf- mass of has increases, density increases
sand sticks to side of the wet cylinder: v of sand+water would be too low
tubing must be at the top of the bottle or volume will decrease and the density will increase
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.
Characteristic Properties- Properties that show differences between substances. Examples: density, boiling point, solubility, melting point.
Density- Mass per unit volume of any substance. Unit of measure is
Sensitivity of Balance- the lightest mass that balance can detect
- before 82: copper/ zinc
- after 82: copper, zinc
Law of Conservation of Mass
- in a closed system, mass will remain constant, regardless of the actions of the processes inside the closed system
Epsom salt: magnesium sulfate
calcium chloride: calcium+chlorine, hydrotropic, mildly acidic
sodium bicarbonate: baking soda