Section 2.3
How reliable are measurements?
Practice Test
1.
How many significant figures will there be when the density value is calculated from the following data? mass = 24.47g; volume =13.2 mL
a.
3
b.
2
c.
4
d.
5
Hint
2.
What is the percent error if a measured value is 24.59 g/mL and the accepted value is 25.49 g/mL?
SC.H.1.4.1
a.
0.0366
b.
1.037
c.
3.50%
d.
0.9647
Hint
3.
The closeness of an experimental value to an accepted value is its ______.
SC.H.1.4.1
a.
error
b.
accuracy
c.
percent error
d.
precision
Hint
4.
Which of the following is not a significant figure?
a.
zeros to the left of the first significant digit
b.
a zero between two digits that have values of 1 through 9
c.
a value of 1 through 9
d.
zeros to the right of a significant digit when a decimal point is present
Hint
5.
Why are plus and minus signs ignored in calculating percent error?
SC.H.1.4.1
a.
Only the size of the error matters, not whether the values in error are larger or smaller than the accepted values.
b.
An experimental value smaller than the accepted value is not considered an error.
c.
Accepted values for data do not include negative numbers.
d.
The formula for percent error automatically cancels out the signs.
Hint
6.
Which of the following numbers has 4 significant figures?
a.
0.05208
b.
0.52089
c.
0.052
d.
0.0521
Hint
7.
A measure of the closeness of a series of measurements is their ___________ .
SC.H.1.4.1
a.
precision
b.
percent error
c.
error
d.
accuracy
Hint
8.
The sum of 4.824 + 2.03 + 4.72319 + 123.4567 + 111.1 expressed to the proper number of significant figures is ____________.
a.
246.1
b.
246.134
c.
246.13
d.
246
Hint
9.
Perform the indicated mathematical operations and report the answer to the proper number of significant figures.
21.55 x 4.12
/42.42
a.
2.09
b.
2.093 0
c.
2.093
d.
2.1
Hint
