CHEM LAB 1-2
How long should eyewash station be used?
15 minutes
With results of 32.9 mL and standard deviation of 0.3 mL. What is the standard way to report the result?
32.9 + 0.3 mL
Accuracy
A description of how close a measurement is to the true value of the quantity measured.
Best practices for safely handling waste in the lab?
Always wear PPE. Check labels or instructions before disposal.
Information needed to communicate with emergency responders
Any chemicals involved in an incident Any hazards present in the lab How the incident happened
Best time to clean glassware after use?
As soon as practical after use
What should you do before you heat glassware on a hot plate?
Check for cracks Inspect plate for frayed cords Ensure glassware is designed for heating
systematic error
Error that shifts all measurements in a standardized way. Decreases accuracy. Can result in bias
Types of signs to convey information about chemical storage?
Hazard signs, NFPA, Gas cylinder
Where should glassware be stored after it is cleaned?
In a drying oven, or designated locations such as drawers or buret racks
How should students prepare to use chemicals in the lab?
Locate the spill kits and understand how they are used. Become familiar with the chemicals to be used, including exposure or spill hazards.
What is the extra step in cleaning up acid and base spills?
Neutralize the spill before cleaning it up.
PASS for fire extinguisher
Pull Aim Squeeze Sweep
Precision
The degree to which repeated measurements show the same result.
What is the best way to smell a chemical sample?
Use your hand to gently waft the smell toward you.
Main precaution for Gas Cylinder
Visually check that gas cylinder is restrained and keep a safe distance around it
When should you remove goggles in the lab?
When everyone in the room is done handling chemicals
systematic error is caused by ____ , while random error is caused by _____
systematic error is caused by improper use of a measuring device , while random error is caused by random fluctuations in a measuring device
What is the last step of any spill cleanup procedure?
Wipe down the affected area with detergent and water.
random error
an error that occurs when the selected sample is an imperfect representation of the overall population