Food Combustion Lab - Revision history

Bes at 21:08, 25 March 2019

2019-03-25T21:08:56Z

Bes at 20:29, 11 March 2018

2018-03-11T20:29:48Z

Bes at 11:40, 17 March 2017

2017-03-17T11:40:50Z

Mgulley: /* Experiment 2 */

2016-04-28T20:44:00Z

Experiment 2

Mgulley: /* Experiment 1 */

2016-04-28T20:41:10Z

Experiment 1

Mgulley: /* Instructions */

2016-04-28T20:40:13Z

Instructions

Mgulley: /* Instructions */

2016-04-28T20:37:53Z

Instructions

Mgulley: /* Step 3. */

2016-04-28T20:27:58Z

Step 3.

Mgulley: /* Experiment 2 */

2016-04-28T20:25:34Z

Experiment 2

Mgulley: /* Experiment 1 */

2016-04-28T20:25:20Z

Experiment 1

← Older revision		Revision as of 21:08, 25 March 2019
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	[[General_Chemistry_(Chem_140)\|...back to Chem 140]]		[[General_Chemistry_(Chem_140)\|...back to Chem 140]]
		+
		+	[[Media:Combustion_lamp_food_lab_WORD.doc\|WORD]]

	[[Media:Combustion lamp food lab.pdf\|PDF]]		[[Media:Combustion lamp food lab.pdf\|PDF]]

← Older revision		Revision as of 20:29, 11 March 2018
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		+	[[General_Chemistry_(Chem_140)\|...back to Chem 140]]
		+
	[[Media:Combustion lamp food lab.pdf\|PDF]]		[[Media:Combustion lamp food lab.pdf\|PDF]]
	==Introduction==		==Introduction==

← Older revision		Revision as of 11:40, 17 March 2017
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		+	[[Media:Combustion lamp food lab.pdf\|PDF]]
	==Introduction==		==Introduction==

@@ Line 70: / Line 70: @@
 where, f is the heat loss factor (average value from three methanol experiments), qw is calculated from  eq 3 and n is the moles of fuel combusted (calculated from the mass).
-Clearly show all calculations in your lab notebook.
+''Clearly show all calculations in your lab notebook.''
 ===Experiment 3===

@@ Line 29: / Line 29: @@
 ===Experiment 1===
-'''Calibration Experiment;Buring Methanol'''
+'''Calibration Experiment: Burning Methanol'''
 It is unreasonable to expect that all of the heat generated from a reaction will be captured by the water. For this reason, we conduct this “calibration” experiment. Following the above procedure, we can collect data to calculate a “heat loss factor” (f) by burning a fuel with a known heat of combustion (Hcomb), in this case methanol (CH3OH). You will use the change in mass of the CH3OH burner, the temperature change, and the amount of heat that should be generated (calculate) to calculate the f; see below.  Collect data for three separate experiments, calculate f for each experiment and then average the f values. Record all data and calculations in your lab notebook. Please check your individual f results with your instructor before proceeding to the next experiment.

@@ Line 8: / Line 8: @@
 ===General Procedure===
-====Step 1====
+=====Step 1=====
 Assemble a calorimeter as demonstrated in the pre-lab introduction. Include a diagram of the apparatus in your lab notebook.
-====Step 2====
+=====Step 2=====
 Working in pairs, you will use a small burner to combust the fuels; practice lighting and extinguishing the burner.
-====Step 3====
+=====Step 3=====
 For each combustion experiment, three experimental parameters required:
@@ Line 25: / Line 25: @@
     Temperature change: We will use the Vernier stainless steel temperature probes to measure an initial temperature (Ti) and a final temperature (Tf), then do the math. We suggest holding the thermometer at all times for three reasons: a) if you sit the thermometer on the very bottom of the can, it may be much hotter than the water itself, b) by holding the thermometer, you can gently agitate the water to allow the heat to dissipate throughout the entire water sample, and c) you are much less likely to “tip over” the apparatus.
-====Step 4====
+=====Step 4=====
 To initiate the experiment, obtain the mass of the burner with cap, and then do the following quickly: a) remove the burner cap, b) light the burner, c) place the water-filled soda can/temperature shield on top of the burner. Monitor the temperature while the fuel combusts, extinguishing the flame once the temperature has risen ~ 20 C. Measure and record the final temperature of the water.
-===*Experiment 1*===
+===Experiment 1===
 '''Calibration Experiment;Buring Methanol'''
@@ Line 58: / Line 58: @@
 Ideally, the water would absorb all the heat generated in the combustion reaction and f = 1.  In reality, there will be heat lost to the environment and the numerator of eq 1 will be smaller than the denominator.  Therefore, the f-factor should be less than 1.
-===*Experiment 2*===
+===Experiment 2===
 '''Assigned Fuel Experiment'''
@@ Line 72: / Line 72: @@
 Clearly show all calculations in your lab notebook.
-===*Experiment 3*===
+===Experiment 3===
 '''Food Fuel Experiment'''

@@ Line 16: / Line 16: @@
 ====Step 3.====
 For each combustion experiment, three experimental parameters required:
-a) the mass of fuel combusted,
+     a) the mass of fuel combusted,
-b) the mass of water heated as a result of combustion, and
+     '''Mass of fuel:''' It is suggested that the burner be massed (weighed) with the cap on at the beginning of an experiment and then again at the end of the experiment.
+     '''Mass of the water:''' The mass of the water used during the experiment is best determined by first measuring the volume in a graduated cylinder (~50 mL) and then determining the exact mass by tarring the “soda can” on the balance and then adding the water.
-c) the change in temperature of the water.
+     '''Temperature change:''' We will use the Vernier stainless steel temperature probes to measure an initial temperature (Ti) and a final temperature (Tf), then do the math. We suggest holding the thermometer at all times for three reasons: a) if you sit the thermometer on the very bottom of the can, it may be much hotter than the water itself, b) by holding the thermometer, you can gently agitate the water to allow the heat to dissipate throughout the entire water sample, and c) you are much less likely to “tip over” the apparatus.
 ====Step 4.====

← Older revision		Revision as of 20:25, 28 April 2016
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	'''Calculating The Heat Loss Factor'''		'''Calculating The Heat Loss Factor'''

−	The f of the calorimeter accounts for the fact that not all heat generated by the combusted fuel goes into the water. The f is the ratio of the heat absorbed by the water (qw) to the heat generated (qf) by burning n moles of fuel.	+	The f of the calorimeter accounts for the fact that not all heat generated by the combusted fuel goes into the water. The f is the ratio of the heat absorbed by the water (qw) to the heat generated (qf) by burning n moles of fuel.(eq 1)
−	(eq 1)