EMPA Flashcards
1
Q
How to accurately determine melting point of a substance in a melting tube?
A
- Heat melting point tube in an oil bath
- Slow down near the melting point
2
Q
Importance of washing inside of a flask when approaching the titration end point. Why doesn’t this affect the titre value?
A
- To make sure all the solutions from both the burette and pipette are in the flask to react with each other
- Water does not change the number of moles of either reactants
3
Q
A
4
Q
When using a pH meter to measure the endpoint, how can we make the endpoint more accurate?
A
Take more pH readings around the end-point by adding smaller volumes of burette sol
5
Q
A
6
Q
Why do we wash solid residues with water
A
Remove soluble impurities
7
Q
Use of anti-bumping granules
A
To prevent vigorous bubbling
8
Q
Why do we measure the atmospheric pressure when boiling something
A
Boiling point varies with pressure
9
Q
Why is boiling point insufficient to identify a substance
A
Many compounds have the same boiling point
10
Q
A
11
Q
How to make sure the pH meter is accurate
A
- Calibrate meter with solutions of known pH/
- Adjust meter if necessary
- Plot calibration curve
