•|Combustion Of Nuts., Back up|•

Introduction………………………………………………………………………………………….

In all chemical reaction a certain amount of chemical required energy is changed into thermal energy, or the other way around. This energy change can be measured as heat released or absorbed during the reaction. The heat absorbed or released during the reaction is measured in kilojoules per mole…and also known as heat of reaction. To measure this amount of heat the “experimental technique called calorimetry” (300) is used.

Q = mcΔT

“Mass (m), temperature change (ΔT) and type of substance are the three factors that are combined to represent the quantity of heat (Q)” (301). Specific heat capacity (c) is the quantity of heat required to raise the temperature of a unit mass of a substance by one degree Celsius or one Kelvin. This varies from substance to substance. I.e. the specific heat capacity of water is 4.18 J/ (g °C)

Similarly, calorie, “c”, is a unit of energy and most commonly known as unit of food energy. Small calorie or gram calorie is the quantity of heat required to raise the temperature of one gram of water by one degree Celsius.

All foods contain energy, but the amount of latent energy stored will vary mainly on the type of food. That stored energy is known as Calories. When we eat food, our bodies convert that energy—calorie—to chemical energy for us to do work. However, we are not supposed to confuse calorie between Calories. Food caloric value is often referred to Calories, “C”; this is actually the same as kilocalorie. One kilocalorie (1 food calorie) is equal to thousand calories. Calories measure the energy you get from the food you eat.

To measure the amount of Calories or calorie in one food, we use calorimeter. A calorimeter is a device that measures the heat generated by a chemical reaction or physical changes or heat capacity. There are different types of calorimeter but the main component for a good calorimeter is insulation; this is to prevent the reaction from losing heat.

For this experiment the food used are nuts. Nut, in general, is a term for dry seed or fruit of some plants…and varies in size and shape. Moreover, nuts are an important source of nutrition for both humans and wildlife. This experiment, however, will help to determine which nut is more fattening or contains more calorie than the other.

Materials …………………………………………………………………………….

Cashew and peanut (or of any nut variety)

Tap Water

Bunsen burner

Tong

250 mL Beaker

Ring clamp/ Iron ring

Retort Stand/ Ring Stand

Thermometer

Electronic Balance

Flint lighter

Home Made Calorimeter

Styrofoam cup

Soda (tin) can

Non-skid paperclips

Procedure……………………………………………………………………………….

Prior to the lab, a simple calorimeter was made out of tin can and Styrofoam. However, the mass of tin can was weighed before the constructions. Fig 1

The retort stand and ring clamp (iron ring) was attached together, and a triangle was placed on top of the ring clamp. From the different kinds of nuts provided, two nuts—cashew and peanut—were chosen and weighed separately. All collected data’s were recorded in under proper names. One of the nuts was set aside for later usage. Using 250 mL beaker—or any proper tools—fifty milliliter of tap water was transferred into the calorimeter. The initial temperature of the water was recorded. The first nut (cashew) was attached to a re-shaped non-skid paperclip so that the nuts would not fall. The nuts and paperclip was picked up by the tong and burnt over the Bunsen burner. As soon as it catches fire, the burning peanut was placed under the calorimeter until the flame falls out. The temperature change was ensured and recorded. The water from the calorimeter was siphoned and replaced with another fifty milliliter. The same procedure was done using the second nut.

Observations…………………………………………………………………………………………

Regular peanut table: Cashew Nut table:

Mass of peanut	0.54 g
Mass of water	50.0 g
Initial water temperature	21.0 C
Final water temperature	26.0 C
Mass of tin can	11.47 g

Mass of cashew nut	1.34 g
Mass of water	50.0 g
Initial water temperature	21.0 C
Final water temperature	40.0 C
Mass of tin can	11.47 g

Calculations…………………………………………………………………………………………

Peanut:

QH20 = (50.0 g) (4.18 J/g ˚C) (26.0-21.0˚C)

= 1, 045 J

Qtin = (11.47 g) (0.213 J/g ˚C) (26.0-21.0˚C)

= 12.21555 J

Qtotal = 1, 045 J + 12.21555 J

= 1, 0572.21555 J

(1, 0572.21555 Joules)(1 cal/ 4.18 Joules)

= 252.9223804 calorie

cpeanut= 252.9223804 c/ 0.54 g ˚C

= 468.4 c/g ˚C

kilocal or Calories (C)

(468.4 c/g ˚C) (1 Calories/ 1000 calories)

= 0.47 kcal/ g ˚C

Cashew:

QH20 = (50.0 g) (4.18 J/g ˚C) (40.0-21.0˚C)

= 3,971 J

Qtin = (11.47 g) (0.213 J/g ˚C) (40.0-21.0˚C)

= 46.41909 J

Qtotal = 3,971 J + 46.41909 J

= 4017.41909 J

(4017.41909 Joules)(1 cal/ 4.18 Joules)

= 961.1050455 calorie

ccashew= 961.1050455 c/ 1.34 g ˚C

= 717.2 c/g ˚C

kilocal or Calories (C)

(717.2 c/g ˚C) (1 Calories/ 1000 calories)

= 0.72 kcal/ g ˚C

Conclusion/ Sources of Error…………………… ………………………………

Cashew contains 0.72 Calories per gram and peanut contains 0.47 Calories per gram. Therefore, cashew is calculated to be more fattening than peanut because of its’ higher Calories per gram, and more work is needed for a person to burn that off.

There are many possible reasons for the lack of inaccuracy in the result that is obtained. One significant error that we may have had done is not burning the peanut, or the cashew, thoroughly. Also, the calorimeter is not fairly constructed and well insulated; some heat might have flow out of the system. Moreover, since everything is done through eyeballing, some digits and data’s collected might have been read wrong.

Peanut:

% Error= [(theoretical – actual)/ actual] x 100

= [(0.47 – 5.7)/ 5.7] x 100

= -91. 2 % or 91.2 %

Cashew:

% Error= [(theoretical – actual)/ actual] x 100

= [(0.72 – 6.4)/ 6.4] x 100

= -88.8 % or 88.8 %

Works Cited:

van Kessel, H., et al. 2003. Chemistry 12. Ontario: Nelson,

Peanut. (2008). Wikipedia: The Free Encyclopedia. Retrieved 28 March 2008, from

<http://en.wikipedia.org/wiki/Peanut>

Cashew. (2008). Wikipedia: The Free Encyclopedia. Retrieved 31 March 2008, from

<http://en.wikipedia.org/wiki/Cashew>

Calorimeter. (2008). Wikipedia: The Free Encyclopedia. Retrieved 28 March 2008, from

<http://en.wikipedia.org/wiki/Calorimeter>

Calorie. (2008). Wikipedia: The Free Encyclopedia. Retrieved 28 March 2008, from

<http://en.wikipedia.org/wiki/Calorie>

Olson, Andrew Ph.D., Science Buddies USC Biology Department, 2004. " 'Burning Calories': The Energy in Food," Biology Department, University of Southern California accessed Retrieved 28 March 2008, from

<http://www.sciencebuddies.org/mentoring/project_ideas/Chem_p017.shtml>

Calorie Lab: Combustion of Nuts

March 20^th 2008

Mitzi Flores

Rachelle Abad, Terry Ji, Yun Kao, Cynthia Yu

SCH4U1-2D

April 7, 2008