Study Guide for Quiz #1
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Reaction in a Bag Lab
- used as a pH indicator
pH scale: measures acidity
- bellow 7 turns yellow (acid)
- above 7 turns pink (alkaline)
- 7 = neutral
Ex:
- lemon juice = 1.5
- tums = 10
Solid A = calcium chloride
- calcium + chlorine
- mildly acidic
- hydro-tropic (attracted to water)
Uses: sports drinks, flavors pickles (salty flavor), canned vegetables (keeps them from getting mushy)
Solid B = sodium bicarbonate (baking soda)
- not acidic
Uses: baking, cat litter, tooth paste, laundry detergent
Red liquid + A + B = Gas
A + liquid = hot (exothermic reaction)
B + liquid = cold (endothermic reaction)
Heating Baking Soda Lab
- the droplets evaporated from the baking soda
- the heated substance is not baking soda
- it is a darker orange when mixed with tea
- it clumps when mixed with tea
- there is less condensation that the heated baking soda because it cannot produce more of something than it has
Experimental Group: heated baking soda
Control Group: unheated baking soda
Indicator: tea
Variable: something you try to measure
- Independent (flame) will cause change in
- Dependent (color of the tea)
Control Factors: things in the lab that you control that would affect the outcome
Ex: same type of tea, amount of baking soda, amount of tea, stir for same amount of time, same size test tube
Volume
Unit cube: 1 cm on each side
Volume = lwh (book uses abc)
Metric System:
1cm = 0.1m or 100cm = 1m
mL = milliliters = 1cm^3
Graduated Cylinders:
- always check intervals
- read from the bottom of the meniscus
Single Pan Balances
2. always zero balance between massing
- push all riders to zero
- use adjustment knob if needed
3. NEVER switch pans
4. pick up balance by red bar only
5. don't zero balance when done
Box Questions
1&2 pg. 5
1. Why do you think baking soda is used in baking? It releases gas when heated which helps dough/batter rise/get fluffy.2. X
3-8 pg. 8
3. 50.0
4. the height and/or width is larger
5. 7cm^3
6.
a. 8
b. 27
c. a = 8cm^3, b = 27cm^3
7. the second box
8. because the cone gets wider as it goes up
9-13 pg. 11&12
9.
a. 1.2, 3.7, no
b. 1.65, 2.51, no
c. because it is more accurate
10.
a. 0.1cm^3
b. 0.2cm^3
11.
a. 4.0 mL
b. 1.26 mL
12.
11.5 - 12.4
11.95 - 12.04
11.995 - 12.004
13. they can be measured more accurately because the lines are further apart because there is more depth
Lab Safety
For Every Lab
- Always wear goggles until Mr. Leeds says to put them away (even ifyou are done)
- report ALL accidents/spills to Mr. Leeds immediately
- nurse ext: 2828
Safety Equipment in classroom
- fire extinguisher
- fire blanket
- eye wash/shower
Chemicals
- never taster chemicals
- always WAFT liquids to detect order
- NEVER waft solids or powders
- always wash hands after the lab
- avoid touching chemicals
- if chemicals touch skin, flush with water for 1 minute and notify Mr. Leeds
Glass
- hot glass and cold glass look the same
- never use chipped or broken glass
- tell Mr. Leeds and dispose of broken glass in proper trash
- never use force to insert or remove glass
Alcohol Burners
- roll up sleeves, put up long hair (not just pull back)
- never walk away from a lit burner
- never point the open end op a hot test tube at yourself or someone else
- do not look down a test tube/beaker while it is being heated
- make sure burner is capped and flame is out when done
End of Experiment
- CLEAN-UP AREA AND MATERIALS COMPLETELY!!!!!
- make certain that the burner is out (if one was used)
- keep goggles on (over eyes) until Mr. Leeds says to put them away.