• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Chem Lab Report (How much energy can we get from margarine)

Extracts from this document...


Daswani 6A (23) Chemistry Lab Report 13 How much energy can we get from margarine? Objective To determine the enthalpy change of combustion of margarine, which is the energy stored in margarine per gram. Principle Margarine is a kind of fat. It can give out energy by burning or by respiration. By using simple calorimetric method, the quantity of this energy can be established. Experimental set-up Chemicals margarine, water Apparatus thermometer, aluminium can, wick, bottle cap, wooden block, tripod Procedure 1.> Fill a bottle cap with margarine up to the rim of the cap. 2.> Smear the whole length of about 4 cm of a thick string (not nylon or synthetic fibre) with margarine. 3.> Push the string into the margarine leaving about 0.5 cm sticking out at the edge of the bottle cap and pointing up like a wick. 4.> Weigh the bottle cap and contents. 5.> Weigh an aluminium can (a used Coke or 7-up can will do) empty. 6.> Measure out 250 cm3 of water in the can. Take the temperature of the water. 7.> Place the bottle cap and contents on top of a wooden block, light the wick with matches and immediately place the can and its contents on a tripod (do NOT add a wire gauze) ...read more.


(4200) (15) kJ = 15750 kJ Energy content of margarine per gram = 15750 � 1.06 = 14.86 kJg-1 Precaution 1.> The distance between the bottle cap and the Coke can should be as close as possible (BUT the wick should not touch the bottom of the can and its burning should not be interrupted) to reduce heat loss. 2.> The temperature of water should close to room temperature at initial, to avoid any extra heat loss to (or gain from) the surroundings, which may increase the percentage error. 3.> The wick should be centered or it will be put off easily since the bottle cap absorb most of its heat. 4.> Wire gauze should not be used, since it will absorb part of heat. 5.> The thermometer should not touch the bottom of the aluminium can and should use it to stir water gently to distribute heat uniformly. Discussion 1.> Using Coke can (made up of aluminium) in this experiment is that the heat can be transmitted ideally to water since aluminium is a good conductor of heat. Besides, aluminium can is so light (relative to 250g of water, it's only 12g) that it's specific heat capacity may be neglected. ...read more.


They are usually esters of glycerol & long chain fatty acids. 5.> Margarine is an artificial fat, made by hydrogenation of vegetable oils. Fat can give us 2 times more of energy (36 - 38 kJg-1) than carbohydrate & protein (16 - 20 kJg-1). The respiratory process inside our body to release energy from fat is similar to combustion in this experiment - they both give out CO2 & H2O. The only difference is that respiratory process release energy more slowly, no light is given out & in a non-vigorous way. Excess fat will store under our skin, around heart & kidney as adipose tissue and cause health problem, e.g. coronary heart disease. Thus, the energy content data of foods is important to people, especially the slimmers. 6.> The experimental energy content of margarine in this experiment is only about 15 kJg-1 which is much lower than natural fat content (36 - 38 kJg-1). This may due to the margarine used is low fat margarine, or due to the experimental errors. Conclusion Simple calorimetry can be used to calculate the energy content of food substance per gram. This values are important to scientists and those people who are on diet. ?? ?? ?? ?? ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Classics section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Classics essays

  1. Chem Lab Report (Paper Chromatography)

    So, when a different solvent is used, amino acids will travel at a different speed. For example, if a more polar solvent is used, the more polar amino acid will travel at a faster speed and has a larger Rf value.

  2. To determine the indicator range of some acid-base indicators

    Within the range between [ In- (aq)]/ [HIn (aq)] < 1/10 to > 10, the color of the solution keeps changing. If [In- (aq)] is smaller than [HIn (aq)], the color would be closer to that of [HIn (aq)]. If [In- (aq)] is larger than [HIn (aq)], the color would be closer to that of [In- (aq)].

  1. media content

    The lighting is a very white light and it emphasises with very little glare and a strongly lit finish of the car. No shadows are shown and highlights on the reflective. All this will have a great effect on the audience.

  2. Determination of Chlorine and Iodine in Water

    .143mol/.100=1.43 molarity of chlorine #3 .001/.0035=.289mol thiosulfate .289mol/2=.143mol chlorine .143mol/.100=1.43 molarity of chlorine Titration of tap water and Iodine solution 1st titration 2nd titration 3rd titration Tap water Iodine Tap water Iodine Tap water Iodine Initial Volume 14.5mL 4mL 18.5mL 16mL 22mL 4mL final Volume 16.5mL 15mL 18.5mL 16mL 22mL

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work