Exam 1 TopHat Questions Flashcards
A sample with a different chemical composition from place to place is a ________ sample?
heterogeneous
True or False: It is essential to obtain a representative sample to analyze
true
After a liquid is used to extract an analyte from a solid sample, the liquid is _____ from the sample.
decanted
Why is a calibration curve, or a standard curve, necessary in chemical analysis?
to measure the detector response for different analyte concentrations
True or False: Random errors can be eliminated and reduced by better techniques
false
Which of the following is NOT a characteristic of random (or indeterminate) error?
it arises from a flaw in equipment or the design of an experiment
The uncertainty of a buret is +- 0.05 mL. The true value of a reading of 17.23 mL is in the range _____?
17.18 to 17.28 mL
True or False: A standard deviation close to zero means that the data points are close to the mean of the set
true
True or False: A standard deviation close to zero means that the points in a data set are close to the “true” value
false
You can decrease the uncertainty by a factor of 4 by increasing the number of measurements by a factor of ______
16
True or False: When Fcalculated is greater than Ftable at the 95% confidence level, there is a less than 5% chance that the two data sets come from the same populations with the same population standard deviation.
true
Which statement is NOT true for the method of least squares?
the equation for a straight line is y = bx +m, where m is the slope and b is the y-intercept
The linear range is _____
the concentration range over which the instrumental response is a linear function of the analyte concentration
A result that says a concentration is below a certain limit but it is actually above a the limit is a ______
false negative
When a reaction is reversed, how is the equilibrium constant of the reversed reaction (K’) related to the equilibrium constant (K) of the original reaction?
K’ = 1/K
