food Chapter 12 Calories Measurement of the energy content in a substance heat Calorie E require to raise the temperature of 1 gram of water 1C Calorimeter is a device that measure the heat produced or absorbed during a process such as chemical reactions or combustion ID: 530028
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Slide1
Calories from
food
Chapter 12 Slide2
Calories
Measurement of the energy content in a substance =
heat
Calorie = E require to raise the temperature of 1 gram of water 1*C
Calorimeter is a device
that measure the heat produced or absorbed during a process such as chemical reactions or combustionSlide3
calories
calorie
(small calorie) is the approximate amount of energy needed to raise the temperature of one gram of water by one degree Celsius
Calorie (
large
calorie
) kilogram calorie, dietary calorie, nutritionist's calorie or food calorie (symbol: Cal
),
1 Cal equal
to 1000 small calories
This
is a small unit so kcal is used
1000 cal = 1 kcal Slide4
calories
q
=(specific heat capacity) (mass)
Δ
T
Δ
T = change in T
-q surrounding = q system why q surrounding + q system = q universe =0Slide5
Calories
The SI unit for energy is
Joule
One small calorie is about 4.2 joules, and one large calorie is therefore 4.2 kilojoules.
Sp
Heat of water in calories is 1.00
cal/g*CDensity of water =1 Slide6
Experiment
Going to burn a food product and measure the heat given off by measuring the temperature of water using a
calorimeter
Under the condition of the experiment the combustion is incomplete so the only part that burns is the fat
The heat of the oil burning is all you are
measuringSlide7
Heat
Basically How many
Calories
(Kcal) from fat of the food.
Ie
.. 200ml
of
water in the soda can.Weight of chip is 0.882g before burningWeight of chip after 0.102gTemperature initial 27.8* C final 37.1*CSlide8
Calculations
SmDT
=q surrounding
Calculte
of q water =
SmDT
q=1.00cal/g*C)(200ml *1g/ml)(37.82-27.8)
q=2004 kcal + because the water is gaining e and is endothermic.q surrounding =-q systemq food= -q water or -2004kcal or
-2.00Cal exothermic releases heat to systemSlide9
Calculations
Kcal or Cal in food, serving size is 20g
Cal serving
/ 20 g = 2.00 Cal/ 0.790g
Doing the math
50.7 Cal in the food per servingSlide10
Calculations
% Error
Label says 180
(50-180/180)*100 =72.2 %Slide11Slide12Slide13