9.1 The following data describes the relationship between Celsius and Kelvin

Celsius , Kelvin

200 , -73.15

300 , 26.85

400 , 126.85

450 , 176.85

500 , 226.85

What's the equation for this relationship ?

Solution:

Insert the data set in the Data: (X Y) text field and calculate. The equation visible in the Function field represent the relationship.

9.2 How many Fahrenheit is 100 oCelsius ?

Celsius , Fahrenheit

-73.15 , -99.67

26.85 , 80.33

126.85 , 260.33

176.85 , 350.33

226.85 , 440.33

Solution:

Insert the data set in the Data: (X Y) text field and calculate. The equation visible in the Function field represent the relationship. Use this equation and calculate Y (X = 100).

9.3 Determine the vapor pressure of butadiene at 0oC knowing following temperature/pressure relationship.

0oC , P (mm Hg)

-61.3 , 40

-55.1 , 60

-46.8 , 100

-33.9 , 200

-19.3 , 400

-4.4 , 760

15.3 , 1520

48 , 3700

76.0 , 7600

Solution:

Insert the data set in the Data: (X Y) text field and select Best Fit . The equation visible in the Function field represent the relationship. Use this equation and calculate Y (X = 0).

9.4 Use following experimental data (time and radiation - counts per second) to determine the half life T1/2 for the Pa[234] isotope.

Time(sec) , radiation (cps)

60 , 66.7

150 , 26.9

240 , 11.0

330 , 4.9

420 , 1.7

Solution:

Insert the data set in the Data: (X Y) text field and select Best Fit. The relationship is represented by the equation Y = A * exp(B*X) visible in the Function field. Use the coeff. B in the generated equation and calculate T1/2 knowing that T1/2 = (ln 2)/B .

9.5 The following data where obtained on the rate of hydrolysis of 16% sucrose in 0.1 mol/L HCl aqueous solutions at 34 oC.

t/min , Sucrose remaining %

9.83 , 96.5

59.60 , 80.2

93.18 , 71.0

142.9 , 59.1

294.8 , 32.8

589.4 , 11.1

What is the order of reaction with respect to sucrose ?

Solution:

Insert the data set in the Data: (X Y) text field and select Best Fit. By the curve, an exact exponential decay, we can conclude that the reaction is of first order.

Chemistry Software - Home