IPS Exam Review

Marvis Gutierrez

Substances

REACTION IN A BAG

The Red Liquid (Phenol Red)

Calcium Chloride (Solid A)

–It's hydrotropic, which absorbs and is attracted to water
–Uses:

  • Canned Veggies (keeps from getting muddy)
  • Electrolytes in Sports Drinks
  • Flavor Pickles (the salty flavor)

Sodium Bicarbonate (Solid B)

–Otherwise known as baking soda
–Uses:
  • Baking
  • Toothpaste
  • Detergent and Cleaners

OTHERS

Condensation

-Comes from warm water vapor in the air (humidity), when in touches the cool surface of the bottle it turns from a gas to a liquid.

Copper Sulphide (The Mass of Copper = Sulfur)

-Sulfur bonds with the copper and forms this substance when the yellow smoke cools.


REACTIONS

  • If (A + Liquid) is combined, it produces an exothermic reaction (hot)
  • If (B + Liquid) is combined, it produces an endothermic reaction (cold)
  • If (A + B + Liquid) is combined, it produces a gas

Terms

(CONTROL GROUP-FACTORS : APPLIES TO HEATING BAKING SODA)


Control Group: the unheated test tube
Experiment Group: the heated tube
Indicator: the Publix tea
Variable (a category you try to measure):
  • Independant: the temperature (burner). it causes a change in the dependant
  • Dependant: the color of the tea
Control Factors:
  • Same type of tea
  • Same amount of baking soda
  • Same amount of tea
  • Same size of the testing tube
-Law of Conservation of Mass:
  • In a closed system, mass will remain constant, regardless of the actions of the processes inside the closed system.
-Sensitivity of Balance
  • The lightest mass that you can expect the balance to pick up.

Formulas and Measurements

Volume = cm3 ; Mass = g ; Density = g/cm3

l x w x h = Volume

M/V (mass over volume) = Density

Sensitivity of a Balance (Sensitivity of a Balance Lab) = Change in Mass/Number of Yes

1 cm3 = 0.1 m

1m = 100 cm3

1 mL = 1 cm3

1 k = 1,000 g

1kg = 2.2 lbs

*Errors*

REACTION IN A BAG

  1. Hole in the bag - wouldn't know gas was being produced.


HEATING BAKING SODA

  1. A hole in tubing (won't see the gas fill the bottle)
  2. Stopper isn't snug (won't see the gas fill the bottle)
  3. Didn't rinse stirring rod before using it in the beginning (messes up color)


MEASURING VOLUME BY DISPLACEMENT OF WATER
  1. The sand could stick to the sides of the wet cylinder (sand and water v. would be too low).
  2. You pour the water into the sand (cant find the air pocket volume)

SENSITIVITY OF A BALANCE

  1. Some lead is on the edges of the groups of paper squares - adding mass
  2. You cut some of the paper squares too short - lessening mass


THE MASS OF DISSOLVED SALT

  1. Clean the pan between mass initial and mass final
  2. Outside of the bottle is wet during the mass initial
  3. Not drying of the cap
  4. Remove the cap before the mass final
  5. not shaking long enough
  6. Cap not on tightly
  7. Spill salt when pouring it into the pottle.


ICE ICE BABY

  1. Not wiping off the condensation
  2. Bottle is wet during the mass initial
  3. Shaking the bottle


THE MASS OF COPPER AND SULFUR

  1. Rubber sheet has a hole
  2. Sheet is not tight on the test tube
  3. Sulfur sticks to the side of the test tube
  4. Clean the pan between the mass initial and mass final


THE MASS OF A GAS

  1. Cap is not tight or not quick enough (leaks out, decrease)
  2. Water in pan during the mi
  3. Cap is wet during the mi
  4. Touch the tablet after the mi


MASS AND VOLUME
  1. Cylinder is wet when you mass (adds mass)
  2. Water splashes out of a graduated cylinder (volume less)
  3. Mass/volume same cylinder twice


DENSITY OF A GAS

  1. Find the volume of a rock before mass (mass increase, density increase)
  2. Paint chipped off object (mass decrease)
  3. Measuring same side twice


DENSITY OF A LIQUID

  1. Not rinsing out cylinder b/w substances
  2. Don't re-mass cylinder for first mass
  3. Outside of cylinder is wet during the mass
  4. Dry out cylinder after massing


DENSITY OF A GAS

  1. Not putting the foil back for mf
  2. Touch the tablet after mi (mass decrease, density decrease)
  3. Break surface of H2O bottle (volume decrease, density increase)
  4. Not having the stopper on tight
  5. Spilling H20 - find volume of bottle

Mass of a Penny

-1943–made of steel and zinc

  • Copper was need for bullets in WWII
  • a 1943 copper penny is sold for $82,500.
-Before 1982*
  • 95% Copper
  • 5% Zinc
-After 1982*
  • 2.5% Copper
  • 97.5% Zinc
*1982- Computer was invented, and copper price increases (have copper wires)

Test Questions

TEST #1

Five IPS scholars use the same single-pan balance to mass their friends ring. None knew the results of the others. Their results are listed in the table below:
  • 1 - 3.752
  • 2 - 3.755
  • 3 - 3.715
  • 4 - 3.756
  • 5 - 3.760
-Did any of the students make a mistake in their massing (use data above)?

  • The range is 0.045 and it's supposed to be between 0.01 - 0.02.


TEST #2

- In all Four Experiments from Chapter 2 the common theme involved investigating changes in mass of different states of matter. You now know that in all the labs there should be no change in mass because:

  • Law on Conservation of Mass


TEST #3

-When finding the density of a liquid the most accurate thing to do is..

  • none of the above
-During the Density of a Gas lab the rubber tubing is incorrectly inserted near the bottom (mouth) of the bottle. This will cause:

  • less gas to collect the bottle
-If the error in the question above is made, it will have the following affect:

  • volume decrease, density increase
-Epsom salt is the marketing name for which chemical compound:

  • Magnesium Sulfate