Exam study guide

study guide

Lab saftey notes

  • Nurse # is 2828 in case of emergency
  • Always wear goggles and an apron during a lab
ALWAYS KEEP GOGGLES ON UNTIL MR. LEEDS SAYS TO TAKE THEM OFF
  • If a chemical spills and/or gets on someone, tell Mr. Leeds

Safety equipment in the classroom:

  • Fire extinguisher
  • Fire blanket
  • Eye wash/eye shower
Chemicals
  • Never taste the chemicals
  • Waft liquids to detect odor but don't waft solids or powders
  • Avoid touching chemicals
  • Always wash hands with soap and water after lab
  • If chemicals touch skin: flush skin with water for 1 min AND notify Mr. Leeds
Glass
  • Hot and cold glass look the same
  • Never use chipped/broken glass and tell Mr. Leeds and dispose of broken glass properly
  • Never use force to remove or insert glass
Alcohol burners
  • Roll up sleeves, pull up long hair (in a bun)
  • Never walk away from a lit burner
  • Never point the open end of a hot end of a test tube at yourself or anyone else
  • Do not look down on test tube while it's being heated
  • Make sure burner is capped and flame is out when done
End of experiment
  • CLEAN UP AREA AND MATERIALS COMPLETELY! (or you lose points) and make sure burner is out if one was used
  • Keep goggles over your eyes unless Mr. Leeds says to put them away

Labs

Reaction in a bag lab

Chemical A: Calcium chloride

-acidic and attracted to water

-used in canned vegies (keeps from getting mushy) electrolyte, and sports drinks

Chemical B: Sodium bicarbonate (baking soda)

-not acidic

-uses are making volcanoes, baking, laundy detergent, brushing teeth, and cleaners

Red Liquid: Phenol red

-used as an indicator

-below 7 turns yellow and above 8 turns pink

Procedure

The purpose of the lab was to record the observations that occur when multiple chemical substances are combined to use my observations to understand the reactions of chemicals.

Conclusion

The purpose of the reaction in a bag lab was to record the observations that occur when multiple chemical substances are combined to use my observations to understand the reactions of chemicals. During the lab we mixed chemical A, chemical B, and red liquid in to a plastic bag. The liquid turned yellow and the bag started to expand. The mixture’s temperature was hot. After that we got a specific formula to test out and ours was A + red liquid. The mixture started to turn purple and it was very hot. I have come to the conclusion that when we mix the chemicals they change temperature, color and produce gas. I’ve come to this conclusion because during the lab the data has showed that if you mix A, B and red together the temperature rises, turns yellow, and produces gas.


Heating Baking Soda

Purpose

To observe and record the reaction that occurs when baking soda is heated.


Conclusion

The purpose of this lab was to observe and record the reaction that occurs when baking soda is heated. While heating the baking soda nothing much happened except gas left the baking soda and water appeared at the top of the beaker. When the tea was added to the heated baking soda and the non-heated baking soda it showed that both substances aren’t the same. They aren’t the same because gas left the heated baking soda. I have come to the conclusion that if you heat baking soda all of the gas will leave the baking soda.


Experimental errors

One example of an experimental error could have been if someone did not rinse off the stirring rod when stirring from tube to tube. Another error could have been the tea had some sort of chemical in it, which could have changed the reaction of the baking soda.


Post lab

-Gas comes from the baking soda

-Control group- unheated baking soda is the control group

-Experimental group- heated baking soda


Notes

Volume of liquids

1ml = 1 cm cubed


-READ FROM THE BOTTOM OF THE MENISCUS

-use graduated cylinders to measure volume and always check intervals or scale units= milliliters (ml) or centimeters cm cubed

Single Pan balance notes

-check that pan is clean and dry

-Never switch pans

-Pick up by red bar only

-Don't zero balance when done

mass, volume, and density notes

Mass and volume


1. objects that are made of the same substance that have the same volume, will have the same mass (regardless of their shape)


2. The mass of an object will double if its volume doubles


3. Objects that have the same volume but are made of different substances will not have the same mass


Density


Mass over volume= density


Aluminum density is always 2.7 g/cm3


Extra notes

  • The chemical name for Epsom salt is Magnesium sulfate
  • When the volume increases the density decreases


TESTS

Chapter one

**CHAPTER ONE IS MAINLY CALCULATIONS


  • Transferring kg to lb divide by 2.2


Measuring by Displacement of water experiment

-Mr. Leeds gave each group different amount of sand because each group gets 40% of air space.


Chapter 2

Mass of Copper and Sulfur:

Error: There could be a hole in the sheet or the sheet isn't tight enough

Explanation: the gas could escape


Ice and water lab:

Error: Condensation forms on the outside of the bottle

Explanation: If someone wiped off the condensation which would cause a decrease in mass

Chapter 3

Wheels per skate board (vertical axis) and number of skateboards (horizontal axis) the arrow on the graph is straight


Mi-Mf is the mass of the gass but Mf-Mi is the change in mass