×
×

# The heating capacity of a calorimeter is known to be 4 ISBN: 9780073401331 38

## Solution for problem 7SE Chapter 3

Statistics for Engineers and Scientists | 4th Edition

• Textbook Solutions
• 2901 Step-by-step solutions solved by professors and subject experts
• Get 24/7 help from StudySoup virtual teaching assistants Statistics for Engineers and Scientists | 4th Edition

4 5 0 384 Reviews
23
4
Problem 7SE

The heating capacity of a calorimeter is known to be 4 kJ/°C, with negligible uncertainty. The number of dietary calories (kilocalories) per gram of a substance is given by C = cH(∆T)/m, where C is the number of dietary calories, H is the heating capacity of the calorimeter, ∆T is the increase in temperature in °C caused by burning the substance in the calorimeter, m is the mass of the substance in grams, and c = 0.2390 cal/kJ is the conversion factor from kilo- joules to dietary calories. An amount of mayonnaise with mass 0.40 ± 0.01 g is burned in a calorimeter. The temperature increase is 2.75 ± 0.02°C.

a. Estimate the number of dietary calories per gram of mayonnaise, and find the uncertainty in the estimate.

b. Find the relative uncertainty in the estimated number of dietary calories.

c. Which would provide a greater reduction in the uncertainty in C: reducing the uncertainty in the mass to 0.005 g or reducing the uncertainty in ∆T to 0.01°C?

Step-by-Step Solution:

Step 1:

The heating capacity of a calorimeter is known to be 4kJ/0C, with negligible uncertainty.The number of dietary calories per gram of a substance is given by C=cH ( , where C is the dietary calories, H is the heating capacity, is the increase in the temperature in  0C, m is the

mass of the substance in grams,and c=0.2390cal/KJ. An amount of mayonnaise with mass

0.40 g is burned in a calorimeter. The temperature increase is 2.75 0C.

We have to find

The estimate of the number of dietary calories per gram of mayonnaise, and the uncertainty in the estimate.The relative uncertainty in the estimated number of dietary calories.Which provide a greater reduction in the uncertainty in C: reducing the uncertainty in the mass to 0.005g or reducing the uncertainty in to 0.01 0C.

Step 2:

Here the number of dietary calories per gram of a substance is given by

C= cH ( /m

Here   H=4,

c= 0.2390, , m = 0.40 , .

So

C = = =  6.57

To find the uncertainty in the number of dietary calories per gram of mayonnaise we have to find the uncertainty of C due to each factor.   = =  2.39 g = = =   -16.4312 g

So the uncertainty due to all factors is = =       0.17

So the  estimate of the number of dietary calories per gram of mayonnaise is

C = ( 6.57 Kcal.  And the uncertainty in the power loss is 0.17.

Step 3 of 4

Step 4 of 4

##### ISBN: 9780073401331

Unlock Textbook Solution