Test 1 Flashcards
1
Q
What is the limiting reagent?
A
The substance that is used up, stops the reaction (the smaller number).
2
Q
What are excess reactants?
A
Reactants that are leftover when a reaction stops.
3
Q
What are the rules of significant figures?
A
- All non-zero digits (1285)
- Final zeroes to the right of the decimal (45.00)
- Zeroes between non-zero digits (30009)
- Exact (defines, counted) numbers have infinite sig figs
- Place holder digits are not significant (0.007)
4
Q
How do we state a measurement?
A
Estimate + and - uncertainty
Estimate: what we think the number is (12.5, 36.0 …)
Uncertainty: interval divided by 2
5
Q
What is accuracy?
A
The closeness to a true or actual value.
6
Q
What is precision?
A
The closeness of repeated measurements to each other.
7
Q
How do we calculate percent error?
A
Measured value - actual value
/ actual value X 100
8
Q
How do we measure precision?
A
- Take the average of repeated measurements
- Subtract the lowest from highest (find range)
- Divide the range by two
- Average + and - range divided by 2
