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Data obtained in the study of a sample of radioactive ore are given below. Prepa

ID: 534286 • Letter: D

Question

Data obtained in the study of a sample of radioactive ore are given below. Prepare a graph of the log of activity in counts per second versus time. Draw the "best straight line" through the data points then derive the equation that relates the sample activity and time from the straight line. Use "log" not "ln" in this exercise. (a) Prepare a graph of the vapor pressure of water, in mmHg versus temperature (K). Temperature, in Kelvins, is the independent variable. (b) Now prepare a graph of ln (vapor pressure) versus 1/T. Determine the slope of the "best straight line" and derive the straight-line equation that relates ln VP and 1/T. Calculate the intercept value by substituting the vapor pressure of water at 373 K in your derived equation. There are five errors made on the graph shown below. Identify each error and state: (a) Why it is an error, and (b) what must be done to correct the error.

Explanation / Answer

the data points are shown below

the plot of log (activity) vs time is shown drawn below.

the best fit is log(activity)= -0.004* time+4.405

2. The data points of vapor pressure vs temperature is shown below and the plot is also shown below.

the data points of lnP vs 1/T is along with the curve is shown below

the equation of best fit is lnP= -5297*1/T+20.89

when T= 373K

lnP= -5297/373+20.89=6.689

3. The errors are the data is not the best fit since there are more data points on one side of curve while there are less data points on the other side of the curve.

The y-intercept has to be drawn for x=0. Draw the best fit using excel and develop an equation

x -axis is not specified. Specify x axis and units.

the equation of best fit is not given which gives the R2 value and an understanding of the best fit.

the scale of x and y axis do not start from origin. Start x and y axis from origin

Temperature(K) Vapor pressure (mm Hg) 273 4 298 26 323 90 348 294 373 760