Lab Safety
True or false: Long hair can be down during lab.
false
Anything that can dissolve the core structure of another material.
Test tubes are used for
observing small scale reactions
What is the base unit for time?
second
Define significant figures
digits in a measurement we know to be true.
This is the only area you can have your goggles off during lab.
by the door, far away from the active lab
What are the 3 types of exposure?
absorption, inhalation, ingestion
What is the function of an Erlenmeyer flask?
mixing and storing solutions
what is the base unit for Termperature?
How many sigfigs in: 0.003060 km?
4
Bob is heating a test tube over a bunsen burner, he is pointing the opening towards his lab partner, stan. How should he keep stan safe from the contents of the tube?
How do we prevent against absorption?
goggles, gloves, closed-toed shoes, lab coats, (any PPE)
Explain the process to measure 3.00g of salt on a mass scale.
1. put a weigh paper or beaker on scale
2. zero/tare the scale
3. add salt slowly until mass reaches 3.00g
Volume is derived from what unit(s)?
length x length x length
Round to 2 SFs: 619001 m
620000 m
Why are crocs not allowed in the lab?
The holes do not effectively cover all surface area.
How do we prevent inhalation?
Fume hood and a well-ventilated room
What would you use to measure 21.5mL of solution? a 25 mL graduated cylinder or 100mL graduated cylinder?
25 mL graduated cylinder
Density is derived from what base unit(s)?
mass and length cubed
31.523cm + 8.12cm =
39.65 cm
Jill comes to lab with her hair ties back, closed toed shoes, and her lanyard on like a good BASIS student. Is she ready for lab?
No, she cannot wear her lanyard during lab.
What is the difference between flammables and combustibles?
Flammabales ignite instantly in the presence of a spark or flame whereas combustibles need more energy exposure before ignition.
Why is the graduated cylinder better at taking liquid measurements than the beaker?
graduated cylinder has a smaller circumference, so you can see the meniscus more clearly, as well as more measurement lines to get a more accurate read.
Each measurement in a data set is consistently greater than the known value by 3.00g. How would you describe that data set?
precise, not accurate
894.0g / 4.6g =
190g