IPS Exam Experience
Chapters 1-3
Lab Safety
- Nurse extension: 2828
- Roll up sleeves and put up hair with burner
- Goggles kept on your face during the lab
- Never use force to remove or insert glass
- Exothermic= heat is given off
Chapter 1
Scientific Method
- Identify problem
- Gather info
- Form hypothesis/theory
- Test the theory- experiment
- Analyze data
- Conclusion
Reaction in a Bag Lab
- Turns yellow and bubbly when substances are mixed
- Hot then cold
- Became thick
- Bag expands (fills with a gas)
- Substance A, B, and some sort of liquid is needed for this reaction to occur
Baking Soda Lab
- Baking soda: sodium bicarbonate
- Releases gas when heated
- Tea indicator
- Heated baking soda had changed, no longer is soda
- Hole in the tubing
- Rubber band snaps off on accident
- Cap the burner too early
- Stopper is not on tight
Volume Notes
- Standard unit of length= meter (m)
- 100 cm= 1 m
- Unit of measurement= cm3
- Volume= l x w x h
Single Pan Balance Notes
- Check that pan is clean and dry
- Always "zero" balance before massing
- Never switch pans
- Pick up balance by red bar only
Measure Volume by Displacement of Water Lab
- Volume of Sand Alone= Sand and Water - Water
- Volume of Air= Volume of Dry Sand and Air - Sand Alone
- Amount of air space in sand is usually around 40%
- Sand sticks to the side of graduated cylinder (effect- volume of sand and water is incorrect)
- Read sand level not the water level (volume of sand and water) (calculations are all wrong)
- Water splashes out when sand is poured (less water at the end)
- Pour sand too fast (overflows funnel)
The Sensitivity of a Balance Lab
- Sensitivity= 0.02g
- Triangle= Delta= change
- Triangle M= change in mass
- Triangle V= change in volume
Chapter 2
The Mass of Dissolved Salt Lab
- All the errors lead to a loss in mass
- Cleaning the pan between the Mi and the Mf leads to a loss in mass
- The cap is not tight (water spills out) leads to a loss in mass
- Spill salt from cap to bottle leads in a loss of mass
- Outside of bottle is wet leads to a loss in mass
The Mass of Ice and Water Lab
- Condensation- when warm water vapor touches the cool bottle it changes from a gas to a liquid
- Not wiping off condensation on the outside
- If you shake the bottle
- Cap not on tight- water evaporates and leaves
- Ice is not fully melted
The Mass of Copper and Sulfur Lab
- Shaking the test tube- sulfur could stick to the side of the test tube
- Rubber sheet could have a hole
- Capping burner before reaction ends
- Rubber sheet is not on tight enough on top of tube
The Mass of a Gas Lab
- Outside of bottle is wet during Mi
- Inside of cap is wet
- When loosening cap, some water could splash out
- Loosen cap not fully
- Cap not on tightly
Chapter 3
The Mass and Volume Lab
- Cylinder is not fully submerged in water
- Water could splash out of the graduated cylinder
- Aluminum cylinder is wet
- Re-mass the same cylinder
Density
- M/V=D
- Unit of Density= g/cm3
- Aluminum= 2.7 g/cm3
- Lead= 11.3 g/cm3
- Brass= 8.5 g/cm3
The Density of Solids Lab
- Find the volume of rock before its mass (mass will be greater)= density will be bigger
- Mix up cubes
- Measure from edge of ruler= volume will decrease= density will increase
The Rock
All have different densities because the rock is formed by many substances being compressed together. Different substances= different densities
The Densities of Liquids Lab
- Cylinders could be contaminated
- Cylinder is wet when massed
- Dry out cylinder after its massed
- Some liquid sticks to inside wall of cylinder (volume decreases= density increases)
- Magnesium sulfate= epsom salt
The Density of a Gas Lab
- Hand does not seal the bottle when removing it
- Foil not there for Mf
- Takes too long to insert tubing
- Taking the stopper off before removing the rubber tubing
- Touching the Alka-Seltzer in the middle of the putting it in the test tube (removing some of the mass)