- wear goggles over eyes until Mr. Leeds say so
- Report all accidents/spills to Mr. Leeds immediately
- Utilize common sense
- Nurse extension is 2828
- Fire extinguisher
- Fire blanket
- Eye wash/shower
- Never taste/touch/directly smell the chemicals (waft the liquids not the solids)
- If chemicals touch skin, flush with water for one minute and tell Mr. Leeds
- Hot glass and cold glass look the same
- Never use chipped of broken glass- if broken throw away
- Never use force to remove or insert glass
- Roll up sleeves, put ip long hair, not just pull back
- Never leave an alcohol burner unattended to
- Never point the open end of a hot test tube at yourself or someone else
- Do not look down into a test tube/beaker while it is being heated
- Make sure burner is capped and flame is out when done
End of Expirement
- Clean up area and materials completely
- Make certain burner is out if one was used
- Keep goggles on (over eyes) until MR. Leeds says to put them away
Lab- Reaction in a Bag
- Phenol red
- used as a ph indicator (below 7 color turns yellow and above 8 turns pink)
- Calcium chloride
- hydrotropic (absorbs water)
- Uses: canned vegetables (keeps veggies from getting mushy), electrolytes, flavor pickles
- Sodium bicarbonate (baking soda)
- not acidic
- Uses: baking, toothpaste, laundry detergent
Reaction: The chemicals turned orange yellow and became foamy. The bag turned hot and inflated with gas that solid B emitted. A crackling sound could be heard.
Experimental errors: hole in the bag (one wouldn't see the gas being produced by the reaction)
Reaction in a Bag demonstration- credit to wardsci
Lab- Heating Baking Soda
- main part of the lab
- emitted a gas when heated
- most of the gas went through the rubber tube and into the bottle, pushing the water out of the bottle and into the container
- some of the gas hit the sides of the stopper and tube, forcing it to reach its dew point and turning it back into a liquid
- when mixed with tea, the heated baking soda turned a different color than unheated baking soda, showing us that it is no longer baking soda
Control group- unheated test tube
Experimental group- heated test tube
Indicator- tea (showed that heated t. tube was not baking soda)
variables- a category you try to measure
independent variable- temperature
dependent variable- tea color
control factors- same tea, amount of baking soda, same amount of tea, same size test tube, same amount time of stirring
Exp. errors- hole in tubing (wouldn't see gas fill bottle), not cleaning stirring rod (contamination)
Heating Baking Soda demonstration- Credits to Kathy O'Connor
Measurement Lab (Volume)
to calculate- length x width x height
standard unit of length- meter (m)
1 centimeter=0.01 meters 100 centimeters= 1 meter
Unit cube- a small cube 1 cm on each edge
Volume of liquids
use a graduated cylinder to measure
always check the intervals or scale
units- milliliters (mL) or cm3
grab by red part to move
make sure number on the black part, holder, and scale all correspond
use common sense
Formulas, Conversions, and Unit
D=M/V or ∆M/∆V Labeled by g/cm3
1 meter=100 centimeters
1 kilogram= 1000 gram
Test #1 Example Questions
If the height of the space was half the length of an edge of a unit cube, what was the volume of the box?
4 . 3 . (7+.5)
12 . 7.5
The volume of the box was 90 cubes.
If the height of the space was .67 the length of an edge of a unit cube, what was the volume of the box?
4 . 3 . (7+.67)
12 . 7.67
The volume of the box was 92.04 cubes.
What is the mass of an iron bar that is 4cm x 5cm x 13cm? (1cm3 of iron has a mass of 7.8g.)
4 x 5 x 13 = 260 260 x 7.8g = 2,028 g
A volume of 87 cm3 of dry sand is added to 46 cm3 of water for a total volume of 104 cm3.
The volume of the water that fills the air spaces must be the same volume as the volume of the air space, therefor the volume of the water that fills the air spaces is 29 cm3.
What is the volume of the water that does not fill the air spaces in the sand?
-Air space -29
that does not fill the air space 17
Heating Baking Soda- See Lab- Heating Baking Soda above
Lab 1.4- There were different substances inside the water (would not fill the sand perfectly).There were large sized substances in the sand such as shells (the water would not fill inside the grains of sand properly so the volume would be lower).
Lab 1.8- The squares could be bigger or smaller on different peoples sheets (the reading would be different)If there was residue on the square, the square would be heavier.
Lab 2.1- If you clean the pan between Mi and Mf, then there will be a substance that was there for one massing but not there for another massing. This will change your final calculation.If when you fill the bottle with water, and water gets on the outside, there will be a substance that was there for one of the massings, but not the other because your hand will absorb the water between massings. This will change your final calculation.
Lab 2.4- If you do not put the cap on all the way, and you shake the bottle to see if the ice has melted yet, then some water will escape. The mass will decrease because there will be less of the substance.If you do not dry the cap, then it will have more mass on the first measurement then it will on all of the other measurements. Therefore, the calculations will be wrong.
Lab 2.5- If a lot of the sulfur powder is against the sides and at the top of the test tube, then the reaction would not be as significant and there would not be as much of a change in mass since most of the powder was not heated.If the rubber sheet is not on all the way, or there is a hole in it, the sulfur powder will escape when it is heated. This will cause a far greater change in mass, since some of the sulfur that was there in the Mi will not be there in the Mf.
Lab 2.6- If you do not close the cap all the way, the gas will escape, so you will not find the mass of the gas.
If you pick up the tablet to put it into the bottle, some of the tablet will get onto your hands. There will be more mass in the Mi than the Mf.
Lab 3.2- If you mix up the three long cylinders, then the cylinder that you massed will be different than the one that you found the volume of. This will cause false data.If you do not dry of the cylinder after you put it in the graduated cylinder, then there will be a gain in mass.
Lab 3.5- If you use the displacement method to find the volume of the rock before you mass it, then there will be water on the rock, which will lead to a gain in mass.If you mix up cube 1 and cube 2 after you find the volume of them, and since cube 2 is heavier than cube 1, then you will have false data.
Lab 3.6- If you do not wash out the cylinder between liquid A and liquid B, then they will mix together and give you false information.If you do not re-mass the cylinder, then the mass of the liquid will be heavier because the water stays on the cylinder, making it heavier.
Lab 3.7-1. If you spill some water when you are measuring the volume of the bottle, then you will have a smaller volume of water.If you break the tablet after the Mi, then some of the alka seltzer with get on your hands and your Mf will be too light.
Test #3 Questions that I got wrong
0.8 kg=800 grams 800 = 21.4 21.4x=800 x= 37.38
ALWAYS REMEMBER TO LABEL EVERYTHING, EVEN THE ∆M!