By: Ally Feeney
Safety equipment in room?
-eye wash/ shower
- always waft liquids
-never waft solids or powders
- avoid touching chemicals
-always wash hands after lab
- if chemicals touch skin, flush skin for 1 minute with water and notify Mr. Leeds right away
-hot glass and cold glass look the same
-never use broken glass
- never use force to remove or insert glass
- roll up sleeves and put up long hair
- never walk away from a lit burner
- never point the open end of a hot test tube at yourself or someone else
-do not look down into a test tube while it is being heated
-cap the burner when done
End of Experiment
-always clean area and materials completely (or lose points)
- keep goggles over eyes
-make sure burner is out
Reaction in a bag lab
To record the observations that occur when multiple chemical substances are combined and to use my observations to understand the reaction of the chemicals
What produces the heat?
Substance A and a liquid
What produces cold?
-Substance b and a liquid
what produces gas?
-Substance A and B with a liquid
-if there was a hole in the bag
What was the red liquid called?
What is Phenol red used for?
- a PH indicator
Range of PH for this lab?
-below 7 turns yellow, above 8 turns pink
What does a PH scale measure?
- the acidity of a substance
Range of a PH scale?
What were the two solids used in this lab?
- Calcium chloride, and sodium bicarbonate (baking soda)
What is calcium chloride used for?
-to absorb water
Baking soda Lab
Purpose: To observe and record the reaction that occurs when baking soda is heated.
What are the lab safety procedure?
Where did the gas come from?
- the baking soda
Where did the droplets on the test tube come from?
- the baking soda
What would be some experimental errors in this lab?
-If the test tube was cracked
-if the inverted bottle had too many air bubbles in it
What was the control group in this lab?
- the unheated baking soda
What was the experimental group?
-the heated baking soda
What was the indicator in this lab and why?
-the tea was the indicator because it showed that the two substances were different
What was the independent variable?
- the temperature
What was the dependent variable?
- color of tea
After heating the baking soda, were both substances the same?
- No if they were the same substance they would have both looked the same when mixed with the tea
What are some control factors of this lab?
-using same tea
-same amount of baking soda
-same type of test tube
-same stirring time
Is the amount of condensation more or less than the amount of baking soda?
- it was less because you cant take more gas than there is baking soda because the baking soda is producing the gas
cm3 (cubic cm)
- 1mL = 1 cm3
What is the formula for volume?
What is the standard unit of length?
- 1 cm= 0.01 m
- 100 cm= 1 m
- units= milliliters or cm3
What is used to measure the volume of liquids?
-check pan is clean and dry
-always zero balance before each massing
- push all riders to zero
-use adjustment knob if needed
-pick up balance by red bar only
-don't zero balance when done
Helps things rise because gas is trying to escape
3) How many cubic centimeters of water are required to fill a graduated cylinder to the 50.0 mL mark?
4) rectangular box A has greater volume than rectangular box B but the length of box A is less than the length of Box B. How is this possible?
width and height on box A is larger
5) Adding a stone to a graduated cylinder containing 25.0 cm3 of water raises the water level int he cylinder to the 32.0 cm3 mark. What is the volume of the stone?
6) A student has cubes that measure 1 cm along each edge
a. how many cubes needed to measure 2 cm along each side?
- 8 cubes
b. 3 cm along each side?
- 27 cubes
c. 3 what is the volume in cubic centimeters of each of the cubes in (a) and (b)
- (a) 8 cm3 (b) 27 cm3
7) One rectangular box is 30 cm long, 15 cm wide and 10 cm deep. A second rectangular box is 25 cm long, 16 cm wide and 15 cm deep. Which box has the larger volume.
- Box #2
8) In figure A shows cone shaped graduate used for measuring the volume of liquids. Why are the divisions not equally spaced?
-its narrower towards the bottom
9) Figure B
a) 1.2 and 3.8, 1.25 and 3.86
b) 1.65, 2.52, and 4.51
c) So that the measurement will be more exact
10) What do these graduated cylinders go by
- figure a- 0.1 cm3 and figure b- 0.5 cm3
11) 4 cm3 and 1.3 cm 3
12- could have been rounded up from 11.5 cm or down from 12.4 cm
12.0- could have been rounded up from 1.7 cm or down from 12.2 cm
12.00- could have been rounded up from 11.9 cm or down from 12.1 cm
13) What is an advantage to making a graduated cylinder narrow and tall rather than short and wide?
- lines are more spread out and easier to read because there is less surface space so it needs more depth
- Mass divided by volume
How do you find the change in mass
- Mass final minus Mass initial
How to find the sensitivity of a balance?
- Delta M divided by number of yes'
Does density change when the substance is the same?
- No always remains the same
What way does scientific notation go?
- to the left= negative
- to the right= positive
How do you find air space?
- volume fo dry sand minus volume of sand alone
How do you find the fraction of sand that is air?
- Air divided by dry sand
What many pounds is 1 kg?
- 2.2 lbs
- 1,000 grams
- 100 cm
How to find the density of a gas?
- Delta M over Delta V
- Sodium bicarbonate
What is the chemical name for epsom salt?
- Magnesium sulfate
What is baking soda used for?
- to make food rise because it releases a gas