Question

Using the equation, calculate a value for absolute zero and a percent error (use C) using the accepted value.

Regression equation: y=0.0155x+0.2782
R = 0.8541

Accepted value: -273.5 C

The equation was found from the following data:

No.	Temperature (C)	Temperature (K)	Pressure (atm)
1	44	317	1.0184
2	57	330	1.0576
3	4	277	0.1963
4	30	303	0.9863
5	65	338	1.2413

Answer 1

If you plot the above points, you will get the following graph-

Here, x-axis is the temperature (in ^oC) and y-axis is the pressure.

The equation you have calculate is correct i.e.

y= 0.0155x+0.2782

Putting y= Pressure (P) and x= Temperature (T), we have,

At absolute temperature, pressure is 0 atm. Thus, we have,

Therefore according to your estimation, the value of absolute temperature is -17.94 ^oC. Unfortunately, this is way off the accepted value of -273.5 ^oC.

% Error = |(Experimental Temperature - Actual Temperature)|/|(Actual Temperature)| x 100

Thus, we have,

% Error = |(-17.94 ^oC - (-273.5 ^oC))/(-273.5 ^oC)|*100 = 93.4%.

Thus, the error is 93.4% and since your value is more than the actual value, you have overestimated the absolute zero by approximately 93.4%. It should have been -273.5 ^oC but you have it as -17.94 ^oC.

Note- The accepted value given in the question is -273.5 ^oC but check once if it is -273.5 ^oC or -273.15 ^oC. In any case, your answer won't differ by much.