Chapter 4: Q8P (page 92)
Repeat Problem 4-7 but use the values 50, 100, and 150 for the standard deviation. Superimpose all three curves on a single graph.
Short Answer
All three curves are plotted on the same graph. The graph is displayed below.

/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none}
Learning Materials
Features
Discover
Chapter 4: Q8P (page 92)
Repeat Problem 4-7 but use the values 50, 100, and 150 for the standard deviation. Superimpose all three curves on a single graph.
All three curves are plotted on the same graph. The graph is displayed below.

All the tools & learning materials you need for study success - in one app.
Get started for free
Set up a spreadsheet to reproduce Figure 4-15. Add error bars: Follow the procedure on pages . Usesyfor the + and - error.
Consider the least-squares problem in Figure 4-11.
(a) Suppose that a single new measurement produces a yvalue of 2.58. Find the corresponding xvalue and its standard uncertainty, .
(b) Suppose you measure yfour times and the average is 2.58. Calculate based on four measurements, not one.
(c) Find the 95%confidence intervals for (a) and (b).
Logarithmic calibration curve. Calibration data spanning five orders of magnitude for an electrochemical determination of p-nitrophenol are given in the table. (The blank has already been subtracted from the measured current.) If you try to plot these dataon a linear graph extending from 0 to and from 0 to , most of the points will be bunched up near the origin. To handle data with such a large range, a logarithmic plot is helpful.
Overwhatrangeisthelog-logcalibrationlinear?
(a) Make a graph of log (current) versus log( concentration). Over what range is the log-log calibration linear?
(b)FindtheequationoftheLine
InTheform
(c) Find the concentration of p-nitrophenol corresponding to a signal of 99.9nA.
(d) Propagation of uncertainty with logarithm. For a signal of 99.9nA, log (concentration) and its standard uncertainty turn out to be . With rules for propagation of uncertainty from Chapter 3, find the uncertainty in concentration.
Students measured the concentration ofHCL in a solution by titrating with different indicators to find the end point.

Is the difference between indicators 1 and 2 significant at the 95%confidence level? Answer the same question for indicators 2 and 3.
Nonlinear calibration curve. Following the procedure in Box 4-2, find how many micrograms of protein are contained in a sample with a corrected absorbance of 0.350in Figure 4-13.
What do you think about this solution?
We value your feedback to improve our textbook solutions.