IPS Exam Study Guide

Lab Safety

  • Nurse ext 2828
  • Remove goggles when Mr. Leeds tells you.
  • Report accidents and spills to Mr. Leeds immediately.
  • Never waft solids/powders.
  • If contact with chemicals occurs, notify Mr. Leeds, and flush skin with water.
  • Hot and cold glass look the same.
  • Put up long hair for Alcohol Burner.
  • Never walk away from a lit burner.
  • Do not look down into a test tube/beaker while it is being heated.
  • Acid must be added to water.
-could cause an exothermic reaction.

-Water is less dnese than acid so it will sit on top of acid and could splash out.

Scientific Method

1. identify problem -the car won't start.

2. gather info -check how much gas there is.

3. form hypothesis/theory -the engine's battery is out.

4. perform experiment -put the jumpers on the engine and start it up.

5. analyze data -turn on the car.

6. conclusion -you go to your destination.

Reaction in a Bag

  • in order for there to be a reaction, you must combine a solid with a liquid.
Scholar Reaction In The Bag Inquiry Demonstration and Lab Activity

Heating Baking Soda

experimental errors:

  • stirring rod contamination
  • stopper not snugly.
  • hole in tubing (bottle would not fill with air)
  • rubber band pops up (breaks)

additional notes:

  • baking soda is used in cooking because it produces a gas that allows food to rise.

Lab 1.1 Heating Baking Soda

Measuring Volume by Displacement of Water

Why were lab groups instructed to use different amounts of sand?

  • the purpose of having different amounts of sand is that about 40% of sand is air.

experimental errors:

  • sand sticks to the side of cylinder. (effect: level of water and sand will be lower)
  • crack in funnel. (effect: wouldn't go in tube, would fall out)
  • pour water into sand. (effect: water sits on sand. makes volume of it too high)
  • read level of sand and not water. (effect: makes volume of sand and water lower)

count, mass, or volume?

  • elevator-count, mass
  • stadium-count
  • bridge-mass
  • bus-count
  • water tank-volume
  • freight car-mass
  • theater-count
  • sauce pan-volume

Lab 1-4 Measuring Volume By Displacement

Sensitivity of a Balance

  • ending mass -initial mass of stopper = change of mass
-change of mass/ # of yes's

experimental errors:

  • pencil marks on paper (adds mass)
  • cutting groups uneven
  • balance not zeroed
  • read balance incorrectly

The Mass of Dissolved Salt

experimental errors:

  • cap is not on tight-water spills out (decrease in mass)
  • cleaning pan between Mi and Mf (decrease in mass)
  • salt spills when pouring into bottle (decrease in mass)
  • not shaking long enough (decrease in mass)
  • cap not dry (decrease in mass)
  • remove cap before Mf (decrease in mass)
  • outside bottle is wet and gets on bottle, then hand, and mass goes down (decrease in mass)

The Mass of Ice and Water lab

  • condensation comes from water vapor touching the cooler surface of the test tube.

experimental errors:

  • not wiping off condensation on outside
  • shaking bottle (water could leak out)
  • ice isn't fully melted
  • bottle (outside) gets wet from putting in ice
  • not drying the bottle/cap
  • removed the cap before Mf

Lab 2-4

The Mass of Copper and Sulfur

experimental errors:

  • rubber sheet not on tightly - gas can come up (decrease in mass)
  • hole in sheet - wouldn't see gas (decrease in mass)
  • shaking test tube (decrease in mass)
  • clean pan between massing (decrease in mass)

2-5 Sulfer and Copper

Mass of a Gas

experimental errors:

  • inside of cap is wet - start reaction (effect: change of mass)
  • cap is not sealed - quickly and tight (effect: change of mass)
  • outside bottle wet during Mi (effect: change of mass)
  • water splashes out when gas is released (effect: change of mass)

Law of Conservation of Mass

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

Lab 2-6 Mass of Gas

Mass and Volume

experimental errors:

  • re-mass a cylinder (might get 2 same numbers)
  • cylinder is wet when massing (mass goes up)
  • not enough water in graduated cylinder (decrease in mass)
  • water splashes out of graduated cylinder (turn graduated cylinder sideways and let object slide through) (decrease in volume)

additional notes:

  • objects that are made of the same substance that have the same volume, will have the same mass (regardless of their shape)
  • the mass of an object will double if its volume doubles
  • objects that have the same volume but are made of different substances will not have the same mass
  • standard unit of length = meter
  • 1m =100 cm =0.01 m

Lab 3-2 Mass and Volume

Density of Solids

experimental errors:

  • measure same side of cube/slab
  • measure from end of ruler and not zero (volume goes down, density goes up)
  • measure rock's volume before massing (mass goes up, density goes up)

additional notes:

  • similar volume, heavier cube - a greater density
  • all have different densities because the rock is formed by many substances being compressed together. Different substances = different densities.
  • if volume goes down, the density goes up

Lab 3-5 Density of Solids

Density of Liquids

experimental errors:

  • contamination cylinder (wet on inside)
-dilutes liquid

-mix substances

  • dry the cylinder after its massed (decrease mass)
  • liquid sticks to inside walls of cylinder (mass and density go up)

additional notes:

  • magnesium sulfate - epsom salt

Density of a Gas

experimental errors:

  • hand not sealed on the bottle, so water leaks out - water is let out and bigger air bubble (volume goes up, density goes down)
  • water in your pan during Mf (mass goes down, density goes down)
  • hole in tubing, stopper not on tight, too slow putting tubing in - smaller air bubble - volume of gas is less. (volume goes down, density goes up)
  • remove stopper before tubing (volume goes up, density goes down)

additional notes:

  • sodium bicarbonate in alka-seltzer.
  • it is important to cover the bottle, so water doesn't leak out of the bottle. Density of water outside and inside are same -nothing will move.
  • the volume is the same as the volume of the gas - water leaves bottle because gas takes its place.
  • you can find the mass of the gas by subtracting the Mf by the Mi (Mf-Mi = change of mass)
  • gas is in alka-seltzer. gas is in Mi because it is locked in the tablet, but released by the water in the Mf because the tablet releases the gas.
  • carbon dioxide is in the sodium bicarbonate.