Glycerol Reaction Lab
The Effect of Temperature on The Viscosity of Glycerol
Research Question: What is the effect of increasing the independent variable of the temperature of glycerol (30ºC, 40ºC, 50ºC, 60ºC and 70ºC) (+ 0.5ºC) using a hotplate and measured using a thermometer (+ 0.05º), on the dependent variable of time (secs + 0.2) taken for 50mL (+ 0.05ml) of glycerol to flow through a 50cm3 burette (+ 0.05cm3) into a 250 mL beaker (+ 12.5 mL) measured by a digital stopwatch (+ 0.2secs), therefore indicating the viscosity of glycerol? Background Information:
Viscosity is a property defined as a liquid’s resistance to flow. When the intermolecular forces are strong within a liquid, there is a higher viscosity. (UC Davis, 2014).
The viscosity of a substance is related to the strength of …show more content…
the intermolecular forces acting between its molecular units. Liquids such as syrups and honey are more viscous as the sugars contain hydroxyl groups (–OH) and therefore can form multiple hydrogen bonds with water and with each other, producing a sticky network which makes flow much more difficult, resulting in a higher viscosity. (Boundless, 2014) Glycerol is a clear, viscous, colourless liquid, and with an increase in temperature, the viscosity of it decreases. (Encyclopedia Britannica, 2014)
The independent values chosen were between room temperature and boiling point, to keep the temperature variables achievable through using only a hotplate and so the glycerol was not evaporated at boiling point, as this would affect viscosity. As the temperature increases, the time taken for the glycerol to flow through the burette and into the beaker will decrease, indicating that higher temperature of glycerol has lower viscosity than lower temperatures of glycerol. This is the trend that will occur in this experiment.
(UC Davis, 2014)
Variables:
Independent Variable: Temperature (+ 0.5 ºC) Different temperatures established by heating liquid on a hot plate and measuring heat using a thermometer (+ 0.5ºC). 30ºC 40ºC 50ºC 60ºC 70ºC
Dependant Variable: Time (+ 0.2 secs) Measured in seconds and will be determined by calculating how long it takes, using a stopwatch (+ 0.2 secs) for glycerol to flow completely from a burette into a 250mL (+ 12.5) beaker.
Controlled Variable Method of Control
The density of the glycerol used to flow through the burette (+ 0.05cm3) This can be controlled by using the same sample of glycerol and the same amount of glycerol (50mL + 0.05mL) for each trial and different independent variable to ensure consistency in this area. By using the same sample of glycerol, the pressure, density and temperature will be the same.
5 cm (+ 0.5cm) distance between the burette and beaker The retort stand and clamp used will allow the 5 cm (+ 0.5cm) distance between the burette and beaker to remain constant between trials and variables.
Vertical angle (180ª) of burette A retort stand and clamp will be used to fasten the burette at a consistent angle and level (in comparison to the beaker) throughout the experiment. This will ensure that the glycerol in the burette does not hit the beaker earlier because it is closer to the beaker, and also ensure that the angle of the burette does not
change.
Room Temperature No fans or air-conditioners/heaters will be on as this can alter temperature measurements. By not allowing these things to be on, it keeps the environment as natural as possible.
The starting temperature (ºC + 0.5ºC) of the thermometer Equipment (eg. Beaker + 12.5mL, thermometer + 0.5 ºC and Burette + 0.05 cm3) of the same brand (eg. Bomex brand of Beaker) will be used to keep the equipment as similar as possible for each trial. Using one piece of each equipment (eg. Beaker + 12.5mL, thermometer + 0.5 ºC, burette + 0.05 cm3) for every trial and measurement would not be reliable, as the starting temperature of the equipment would differ due to the heating involved in the experiment. If there is not enough access to the number required for each equipment, the equipment used, must be washed thoroughly with soap for one minute and dried with a paper towel and then left to cool until it is room temperature.
Insertion of thermometer at the 25mL (+ 12.5mL) mark on the beaker. The thermometer will be immersed into the beaker at the 25 mL (+ 12.5mL) mark and not placed in the bottom corner, so the temperature measurement is as accurate as possible for the whole entity of the glycerol.
Reliability:
By ensuring these variables are controlled, it will aid in making the experiment and results more reliable. To ensure the results are reliable, each temperature can be repeated 3 times to decrease the effect of random errors. Five variations of the independent variable (temperature ºC), will also allow sufficient data to be withdrawn from the experiment. A mean value for the three trials will be calculated in order to gain the most accurate time measurement for the glycerol fallen from the burette into the beaker. A clear transparent beaker will also be used so qualitative data will be easier to observe.
Materials:
- Stopwatch x1 (+ 0.2 seconds)
- 50 cm3 Burettes (+ 0.05cm3) x15
- 31 cm square Heatproof Mat x2
- 240 V.AC. Hot Plate x1
- 24 cm Clamp x1
- 11.5 cm Boss Head x1
- 60 cm Retort Stand x1
- 0-100º Thermometer x15 (+ 0.5ºC) (Brand:Initial)
- 250mL Beaker x15 (+ 12.5mL) (Brand:Bomex)
- 2L Glycerol
- 30 cm Ruler x1 (+ 0.5cm)
- Heat Proof Gloves x1 pair
- 50 mL Measuring Cylinder x1 (+ 0.5mL) (Brand:Bomex)
- Funnel x1
Risk Assessment:
- Dispose of the Glycerol appropriately by flushing it down the sink as it dissolves in water and is not harmful to the environment.
- Take care when handling glassware eg. Thermometers, beakers, stirring rod and capillary tubes, to minimize breakage keep glassware away from the edges of the bench and be careful when holding and moving them around.
- After each trial, leave equipment for 2 minutes to cool. After this, when moving hot capillary tubes, gauze mats and beakers, use the heat proof gloves provided to prevent burning skin
- Wear safety goggles to prevent hot glycerol from splashing into eyes.
Method:
1. Place the Hot Plate on the heat proof mat
2. On the other heat proof mat, set up the retort stand with one boss head and one clamp.
3. Attach the 50 cm3 + 0.05cm3 burette to the clamp so the bottom of the burette is 15cms above the heat proof mat. Measure this using a 30 cm (+ 0.5cm) ruler. Make sure the stopcock is 180º so it is horizontal not allowing any liquid that will be added to seep through.
4. Pour 50mL + 0.5mL of the glycerol, into the 250 mL (+ 12.5mL) beaker using the 100mL + 1 mL measuring cylinder.
5. Place the beaker filled with glycerol on the hot plate
6. Turn the dial on the hot plate to the number four
7. Using a thermometer, monitor the temperature of the glycerol. Do not place thermometer in the corner of the beaker as this will not give an accurate reading of the temperature of the whole entity of the glycerol. Instead hold the thermometer in the middle of the beaker, not touching the bottom.
8. Once the thermometer reaches 30ºC + 0.5ºC remove the beaker from the hot plate using Heatproof gloves.
9. Using the funnel, pour the heated glycerol into the beaker
10. Place this same beaker underneath the bottom of the Burette
11. Rotate the stopcock to a 90º angle so it is vertical and immediately start the stopwatch
12. Once the last drop of glycerol has hit the bottom of the beaker, stop the stopwatch
13. Record time taken (secs) for all the glycerol to transfer from the burette into the beaker.
14. Repeat steps 3-13 on the other four temperatures (40ºC, 50ºC, 60ºC, 70ºC) (+ 0.5ºC) of the glycerol first so that the variables will be spread across a range of different conditions (eg. Weather changes), using a new burette (+ 0.05cm3), beaker (+ 12.5mL) and thermometer (+ 0.5ºC) of every trial and different variable of temperature. Using different variables of temperature will allow a trend to be observed between the increasing independent variable and dependent variable values. Using new equipment after each trial and variable will ensure a uniform temperature of the equipment each time.
15. Repeat Steps 3-14 two more times so there are 3 trials for each independent variable, with the same temperature of the glycerol (30ºC + 0.5ºC) using a different burette (+ 0.05cm3), beaker (+ 12.5mL) and thermometer (+ 0.5ºC). This repeat will ensure reliability of the experiment.
16. Record the results in the table below:
Temperature of Glycerol (+ 0.5ºC) Trial Time taken for glycerol to transfer from the Burette into the beaker (+ 0.2 secs) Average time taken for glycerol to transfer from burette to beaker (+ 0.2 secs)
30 1 2 3
40 1 2 3
50 1 2 3
60 1 2 3
70 1 2 3
Qualitative Observations:
Assumptions:
- Temperature of glycerol was uniform throughout the beaker
- No impurities
- No Heat loss occurred when the glycerol was taken off the heat plate and transferred into the burette
References:
UC Davis GeoWiki by University of California. (2013). Viscosity. Retrieved November 2014, from http://chemwiki.ucdavis.edu/Physical_Chemistry/Physical_Properties_of_Matter/Bulk_Properties/Viscosity
Boundless Chemistry by Boundless (2014). Viscosity. Retrieved 23 November 2014 from https://www.boundless.com/chemistry/textbooks/boundless-chemistry-textbook/liquids-and-solids-11/liquid-properties-85/viscosity-377-588/
Encyclopedia Britannica,. (2014). glycerol | chemical compound. Retrieved 3 February 2015, from http://www.britannica.com/EBchecked/topic/236029/glycerol
Research Question: What is the effect of increasing the independent variable of the temperature of glycerol (30ºC, 40ºC, 50ºC, 60ºC and 70ºC) (+ 0.5ºC) using a hotplate and measured using a thermometer (+ 0.05º), on the dependent variable of time (secs + 0.2) taken for 50mL (+ 0.05ml) of glycerol to flow through a 50cm3 burette (+ 0.05cm3) into a 250 mL beaker (+ 12.5 mL) measured by a digital stopwatch (+ 0.2secs), therefore indicating the viscosity of glycerol? Background Information:
Viscosity is a property defined as a liquid’s resistance to flow. When the intermolecular forces are strong within a liquid, there is a higher viscosity. (UC Davis, 2014).
The viscosity of a substance is related to the strength of …show more content…
the intermolecular forces acting between its molecular units. Liquids such as syrups and honey are more viscous as the sugars contain hydroxyl groups (–OH) and therefore can form multiple hydrogen bonds with water and with each other, producing a sticky network which makes flow much more difficult, resulting in a higher viscosity. (Boundless, 2014) Glycerol is a clear, viscous, colourless liquid, and with an increase in temperature, the viscosity of it decreases. (Encyclopedia Britannica, 2014)
The independent values chosen were between room temperature and boiling point, to keep the temperature variables achievable through using only a hotplate and so the glycerol was not evaporated at boiling point, as this would affect viscosity. As the temperature increases, the time taken for the glycerol to flow through the burette and into the beaker will decrease, indicating that higher temperature of glycerol has lower viscosity than lower temperatures of glycerol. This is the trend that will occur in this experiment.
(UC Davis, 2014)
Variables:
Independent Variable: Temperature (+ 0.5 ºC) Different temperatures established by heating liquid on a hot plate and measuring heat using a thermometer (+ 0.5ºC). 30ºC 40ºC 50ºC 60ºC 70ºC
Dependant Variable: Time (+ 0.2 secs) Measured in seconds and will be determined by calculating how long it takes, using a stopwatch (+ 0.2 secs) for glycerol to flow completely from a burette into a 250mL (+ 12.5) beaker.
Controlled Variable Method of Control
The density of the glycerol used to flow through the burette (+ 0.05cm3) This can be controlled by using the same sample of glycerol and the same amount of glycerol (50mL + 0.05mL) for each trial and different independent variable to ensure consistency in this area. By using the same sample of glycerol, the pressure, density and temperature will be the same.
5 cm (+ 0.5cm) distance between the burette and beaker The retort stand and clamp used will allow the 5 cm (+ 0.5cm) distance between the burette and beaker to remain constant between trials and variables.
Vertical angle (180ª) of burette A retort stand and clamp will be used to fasten the burette at a consistent angle and level (in comparison to the beaker) throughout the experiment. This will ensure that the glycerol in the burette does not hit the beaker earlier because it is closer to the beaker, and also ensure that the angle of the burette does not
change.
Room Temperature No fans or air-conditioners/heaters will be on as this can alter temperature measurements. By not allowing these things to be on, it keeps the environment as natural as possible.
The starting temperature (ºC + 0.5ºC) of the thermometer Equipment (eg. Beaker + 12.5mL, thermometer + 0.5 ºC and Burette + 0.05 cm3) of the same brand (eg. Bomex brand of Beaker) will be used to keep the equipment as similar as possible for each trial. Using one piece of each equipment (eg. Beaker + 12.5mL, thermometer + 0.5 ºC, burette + 0.05 cm3) for every trial and measurement would not be reliable, as the starting temperature of the equipment would differ due to the heating involved in the experiment. If there is not enough access to the number required for each equipment, the equipment used, must be washed thoroughly with soap for one minute and dried with a paper towel and then left to cool until it is room temperature.
Insertion of thermometer at the 25mL (+ 12.5mL) mark on the beaker. The thermometer will be immersed into the beaker at the 25 mL (+ 12.5mL) mark and not placed in the bottom corner, so the temperature measurement is as accurate as possible for the whole entity of the glycerol.
Reliability:
By ensuring these variables are controlled, it will aid in making the experiment and results more reliable. To ensure the results are reliable, each temperature can be repeated 3 times to decrease the effect of random errors. Five variations of the independent variable (temperature ºC), will also allow sufficient data to be withdrawn from the experiment. A mean value for the three trials will be calculated in order to gain the most accurate time measurement for the glycerol fallen from the burette into the beaker. A clear transparent beaker will also be used so qualitative data will be easier to observe.
Materials:
- Stopwatch x1 (+ 0.2 seconds)
- 50 cm3 Burettes (+ 0.05cm3) x15
- 31 cm square Heatproof Mat x2
- 240 V.AC. Hot Plate x1
- 24 cm Clamp x1
- 11.5 cm Boss Head x1
- 60 cm Retort Stand x1
- 0-100º Thermometer x15 (+ 0.5ºC) (Brand:Initial)
- 250mL Beaker x15 (+ 12.5mL) (Brand:Bomex)
- 2L Glycerol
- 30 cm Ruler x1 (+ 0.5cm)
- Heat Proof Gloves x1 pair
- 50 mL Measuring Cylinder x1 (+ 0.5mL) (Brand:Bomex)
- Funnel x1
Risk Assessment:
- Dispose of the Glycerol appropriately by flushing it down the sink as it dissolves in water and is not harmful to the environment.
- Take care when handling glassware eg. Thermometers, beakers, stirring rod and capillary tubes, to minimize breakage keep glassware away from the edges of the bench and be careful when holding and moving them around.
- After each trial, leave equipment for 2 minutes to cool. After this, when moving hot capillary tubes, gauze mats and beakers, use the heat proof gloves provided to prevent burning skin
- Wear safety goggles to prevent hot glycerol from splashing into eyes.
Method:
1. Place the Hot Plate on the heat proof mat
2. On the other heat proof mat, set up the retort stand with one boss head and one clamp.
3. Attach the 50 cm3 + 0.05cm3 burette to the clamp so the bottom of the burette is 15cms above the heat proof mat. Measure this using a 30 cm (+ 0.5cm) ruler. Make sure the stopcock is 180º so it is horizontal not allowing any liquid that will be added to seep through.
4. Pour 50mL + 0.5mL of the glycerol, into the 250 mL (+ 12.5mL) beaker using the 100mL + 1 mL measuring cylinder.
5. Place the beaker filled with glycerol on the hot plate
6. Turn the dial on the hot plate to the number four
7. Using a thermometer, monitor the temperature of the glycerol. Do not place thermometer in the corner of the beaker as this will not give an accurate reading of the temperature of the whole entity of the glycerol. Instead hold the thermometer in the middle of the beaker, not touching the bottom.
8. Once the thermometer reaches 30ºC + 0.5ºC remove the beaker from the hot plate using Heatproof gloves.
9. Using the funnel, pour the heated glycerol into the beaker
10. Place this same beaker underneath the bottom of the Burette
11. Rotate the stopcock to a 90º angle so it is vertical and immediately start the stopwatch
12. Once the last drop of glycerol has hit the bottom of the beaker, stop the stopwatch
13. Record time taken (secs) for all the glycerol to transfer from the burette into the beaker.
14. Repeat steps 3-13 on the other four temperatures (40ºC, 50ºC, 60ºC, 70ºC) (+ 0.5ºC) of the glycerol first so that the variables will be spread across a range of different conditions (eg. Weather changes), using a new burette (+ 0.05cm3), beaker (+ 12.5mL) and thermometer (+ 0.5ºC) of every trial and different variable of temperature. Using different variables of temperature will allow a trend to be observed between the increasing independent variable and dependent variable values. Using new equipment after each trial and variable will ensure a uniform temperature of the equipment each time.
15. Repeat Steps 3-14 two more times so there are 3 trials for each independent variable, with the same temperature of the glycerol (30ºC + 0.5ºC) using a different burette (+ 0.05cm3), beaker (+ 12.5mL) and thermometer (+ 0.5ºC). This repeat will ensure reliability of the experiment.
16. Record the results in the table below:
Temperature of Glycerol (+ 0.5ºC) Trial Time taken for glycerol to transfer from the Burette into the beaker (+ 0.2 secs) Average time taken for glycerol to transfer from burette to beaker (+ 0.2 secs)
30 1 2 3
40 1 2 3
50 1 2 3
60 1 2 3
70 1 2 3
Qualitative Observations:
Assumptions:
- Temperature of glycerol was uniform throughout the beaker
- No impurities
- No Heat loss occurred when the glycerol was taken off the heat plate and transferred into the burette
References:
UC Davis GeoWiki by University of California. (2013). Viscosity. Retrieved November 2014, from http://chemwiki.ucdavis.edu/Physical_Chemistry/Physical_Properties_of_Matter/Bulk_Properties/Viscosity
Boundless Chemistry by Boundless (2014). Viscosity. Retrieved 23 November 2014 from https://www.boundless.com/chemistry/textbooks/boundless-chemistry-textbook/liquids-and-solids-11/liquid-properties-85/viscosity-377-588/
Encyclopedia Britannica,. (2014). glycerol | chemical compound. Retrieved 3 February 2015, from http://www.britannica.com/EBchecked/topic/236029/glycerol