Physical Properties of Water
Essay by Joyeew99 • August 21, 2018 • Book/Movie Report • 1,374 Words (6 Pages) • 757 Views
Experiment 1: Physical properties of water
Venue: Food Analysis Lab 3508
Objectives
- To understand factors affecting boiling rate and boiling point of water.
- To determine the effect of varying relative humidity on the water activity of foods.
- Boiling rate of the various amounts of water
Materials
250mL beaker (x1), magnetic stirring hot plate (x1), glass rod, thermometer (x1), timer/stop watch (x1), safety goggles (x1 for each student).
Procedures
Part A(i)
- The heat on the hot plate was turned on at no.8 for 10 minutes. Be careful of the hot surface after turning on the hot plate.
- 200mL of water was poured into a 250mL beaker. The beaker of water was put on the hot plate and a thermometer was put inside the beaker.
- The temperature of water was recorded every 30seconds until the water boils. Then the temperature was recorded every 1 minute for 6 minutes. Subsequently the temperature was recoded every 2 minutes until there is 150mL of water left in the beaker.
- The data was recorded in a template as shown in Table 1.
Part A(ii)
Steps 1-4 in part 1A(i) was repeated with 150mL of water and the heating is continued until there is 100mL of water left in the beaker.
Results
Table 1. Time required to boil 200mL & 150mL of water.
Time (s) | Temperature for 200mL of water ( ℃ ) |
0 | 26.0 |
30 | 28.0 |
60 | 30.5 |
90 | 33.0 |
120 | 35.5 |
150 | 38.5 |
180 | 41.5 |
210 | 43.0 |
240 | 48.0 |
270 | 51.0 |
300 | 54.5 |
330 | 58.0 |
360 | 61.0 |
390 | 64.5 |
420 | 68.0 |
450 | 71.5 |
480 | 74.0 |
510 | 77.0 |
540 | 80.0 |
570 | 83.0 |
600 | 86.0 |
630 | 88.0 |
660 | 91.0 |
690 | 93.0 |
720 | 96.0 |
750 | 98.0 |
780 | 100.0 |
840 | 101.0 |
900 | 101.5 |
960 | 101.0 |
1020 | 101.0 |
1080 | 100.0 |
1140 | 101.0 |
1260 | 102.0 |
1380 | 101.0 |
1500 | 101.0 |
1620 | 101.0 |
1740 | 101.0 |
1860 | 101.0 |
Table and graph for experiment A(i)
[pic 1]
The temperature for 200mL of water is directly proportional to the time.
Table and graph for experiment A(ii)
Time (s) | Temperature for 150 mL of water ( ℃ ) |
0 | 26.0 |
30 | 28.0 |
60 | 31.0 |
90 | 35.0 |
120 | 38.0 |
150 | 42.0 |
180 | 46.0 |
210 | 50.0 |
240 | 53.0 |
270 | 57.0 |
300 | 61.0 |
330 | 65.0 |
360 | 68.0 |
390 | 71.0 |
420 | 75.0 |
450 | 79.0 |
480 | 81.0 |
510 | 84.0 |
540 | 88.0 |
570 | 90.0 |
600 | 92.0 |
630 | 96.0 |
660 | 100.0 |
720 | 100.0 |
780 | 100.0 |
840 | 100.5 |
900 | 100.0 |
960 | 100.0 |
1020 | 100.0 |
1140 | 101.0 |
1260 | 102.5 |
1380 | 100.0 |
1500 | 100.5 |
1620 | 100.5 |
1740 | 100.0 |
[pic 2]
The temperature for 150mL of water is directly proportional to the time.
Discussion questions
- Do the curves in part A(i), (ii) and have a flat section? If so, explain the flat section.
Yes they do, the flat sections show that the temperature could no longer increase beyond 100℃ this is because it already reaches its boiling point. The temperature of a solid, liquid or gas will remain constant during a phase change, assuming its surrounding pressure is constant. Once the temperature of a liquid reaches its boiling point, the temperature will not increase until all the liquid has changed its phase to become a gas. (3)
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