Lab Safety
What should you wear on your face in a chemistry lab?
Safety goggles
How many significant figures (sig. figs) are in this number?
2.55
3
What is the equation for percent error? What can it be abbreviated to?
measure-accepted/accepted
m-a/a
What is the formula for density?
D=m/v
What metric unit is used to measure mass?
Gram
What should you do if there is a fire, and Mr. Delancey is not in the room/nearby
Use the fire extinguisher to put it out
0.0004?
1
While testing the efficiency of a sample of gasoline, a quality control officer found the sample to be 74.1% efficient. The government standard for gasoline is 75.4%. What is the percent error for the calculations?
-1.72%
Calculate the volume of 50.0g of sodium chloride
(sodium chloride density: 2.16 g/ml)
V=23.1ml
What is the difference between an observation and an inference?
An observation is when you know something for sure, and it comes from the 5 senses. An inference is a conclusion based on an observation(s)
What should you do if you get chemicals in your eyes or on your clothes?
4.0500
5
The density of a piece of sodium was measured during a lab and found to be 1.02g/ml. Using the density of sodium found on table S, determine the percent error
5.2%
What mass would 18.0ml of magnesium occupy?
(magnesium density=1.74g/ml)
M=31.3g
Which metric unit is used to measure time?
Seconds
What should you wear to cover your clothes in the chemistry lab?
Apron
100.0
4
Measured=7.952
Accepted: 7.87
1.04%
A substance is measured to be 5cmx5cmx5cm and has a mass of 224g. Choose which material it is:
A:Benzene (0.880 g/ml)
B:Magnesium (1.74 g/ml)
C: Sodium Chloride (2.16 g/ml)
D: Aluminum (2.70 g/ml)
B
Which metric unit is used to measure energy?
Joule
Name 3 things you should always be sure to do while preparing for a lab:
-Tie hair back
-Roll up sleeves
-Don't wear baggy clothing
0.0060
2
Measured: 12.5
Accepted: 12.4
0.81%
A 55.0g piece of material was found to have a volume of 5.40ml. What is the identity of the material?
Silver
Explain the difference between qualitative and quantitative data
Qualitative: Data that uses the 5 senses (ex: hear a high pitched scream)
Quantitative: Data that involves a number (ex: 15.2 cm)