Lab Safety-Measurement Lab
For every lab:
- goggles must be kept over your eyes at all times
- report ALL accidents to Mr. Leeds
- Common sense
- fire extinguisher
- fire blanket
- eye wash/ shower
- never taste
- waft liquids (never solids or powders)
- avoid touching
- wash hands with soap and water
- if chemicals touch skin- flush skin with water for 1 min AND notify Mr. Leeds
- hot glass looks like cold glass
- never use chipped or broken glass
- never use force to remove or insert glass
- roll up sleeves, put UP long hair
- never walk away from lit burner
- never point open end of hot test tube at yourself or someone else
- do not look down into test tube/beaker while being heated
- cap flame when done
End of Experiment:
- clean-up area
- make sure burner is out
- keep goggles over eyes until Mr. Leeds says to put them away
Reaction In a Bag
What was the red liquid?
- measures acidity
- goes from 0-14
- 0 is acidic
- 7 is neutral
- 14 is alkaline
- below 7 turns yellow
- above 8 turns pink
What was Solid A?
Was solid a acidic, neutral, or alkaline?
absorbes/ attracted to water
Calcium Chloride uses?
- canned veggies (keeps from getting mushy)
- electrolyte in sports drinks
- flavor pickles (salty flavor)
What was Solid B?
Was solid b acidic, neutral, or alkaline?
Sodium bicarbonate uses?
- laundry detergent
Another name for sodium bicarbonate?
What is a ph indicator?
AB and water or red
A mixing with red or water (exothermic reaction)
- if there was a hole in the bag we would not see the gas being produced by the reaction
Scholar Reaction In The Bag Inquiry Demonstration and Lab Activity
Heating Baking Soda
What do you observe at the bottom of the test tube?
test tube was getting scorched on the outside
What do you observe near the top of the test tube?
condensation (moisture), bubbles forming, foggy, misty
What do you observe in the inverted bottle?
air is coming in and water is coming out
Where do you think the gas came from?
gas came from Baking Soda; gas left test tube
Where did the droplets on the test tube come from?
Describe the color of the liquid in each test tube.
Heated- murky, cloudy, darker
Unheated- clear, see through, light
ARe the two white powders the same substance?
no because the unheated is only baking soda and tea so the heated should be the same color, but they are different
In the heated test tube, did the baking soda dissolve into the tea?
In the unheated test tube, did the baking soda dissolve into the tea?
What was the control group?
unheated baking soda and tea
What was the experimental group?
heated baking soda and tea
a category you try to measure
causes a change in the dependent variable
example of independent variable
example of dependent variable
- using same tea for both test tubes
- same amount of baking soda and tea
- same size test tubes
- same amount of stirring time
- hole in tubing -> won't see gas fill bottle
- stopper not snug -> won't see gas fill bottle
- not cleaning stirring rod -> contamination
Is the amount of condensation that forms at the top of the heated test tubes more or less than the amount of baking soda being heated?
less because the condensation comes from the baking soda and it cannot produce more than itself
Why does baking soda rise?
when heated it releases a gas
Lab 1.1 Heating Baking Soda
What unit of measurement is used for volume?
cm3 (cubic centimeters)
How do you measure volume?
L x W x H
What is the standard unit of length?
1 centimeter = ______________ meters
100 cm = ____________ m
What do you use to measure volume?
When measuring volume what do you always need to check?
intervals of scale
1 mL = ____________cm3
1 cm3 = _____________mL
How do you "zero" balance a scale?
- push all riders to zero
- use adjustment know if needed
Single Pan Balance
When using a pan balance, what do you never switch?
Pick up balance by _________________ only
Why should you report the positions of the arrows to the nearest 0.01 cm and not to the nearest 0.1 cm?
it will be more accurate
What advantage is there to making graduated cylinders narrow and tall rather than short and wide?
lines are further apart because there's more depth due to lack of surface, therefore it will be easier to read
By Kaitlyn Ockerman