Tomoyo Onda

IB Biology HL Per. 4

Feb 21. 2010

Mr. Stantus

Extreme Temperature Affects to % Change in Mass of Dry Rice

Introduction:

This experiment aims to analyze the relationship between extreme temperature

and the rate of osmosis by absorption (% change in mass). In the daily life, people eat

rice almost everyday and it becomes taste good because it absorbs water. According to

this, people wander that how much water is absorbed into rice depends on the

temperature of pure water. Behavior can be broadly defined as the way organisms

respond to their environment. Diffusion is passive movement of particles from a region

of higher concentration to a region of lower concentration. Osmosis is diffusion of water

across a semipermeable membrane. Some materials are able to easily pass through

membranes while others cannot. Water will always move from an area of higher water

potential to an area of lower water potential. Rice absorbs water until it reaches its

saturation point. For example, cooking rice; people add water into the rice-

cooker and in the next couple of minutes the water has be absorbed the rice

has increased in volume. The environment condition which may affect the extreme

low and high temperature. Rice may rely on the temperature which affect to their rate of

osmosis and the weight of itself. This correlation, between temperature and % of

osmosis, is what this experiment aims to determine. The purpose of this investigation is

to analyze how extreme temperature affects to the % change in mass.

This investigation will formulate and test a hypothesis for each experiment. As

increase the degree of temperature, the rate of osmosis gets faster and increases the %

change of mass because rice absorbs more water when rice is boiled according to a daily

cooking.

Variables:

Independent variable: extreme temperature (0℃, 25℃, 50℃, 75℃, 100℃)

Dependent variable: % change in mass of rice

Controlled variables: temperature of a room, amount of pure water (200ml), size of a

beaker, time of experiment (20 min), type of rice, amount of rice, condition of rice

(dried),

Materials:

-5 beakers

-Dried rice

-Pure water

-Cling film　

-Stop watch

-thermometer

-incubator

-weight measure

-ice

-camera

Procedure:

1.

Prepare 5 beakers and put same

amount of pure water for each.

2. Put same amount of dried rice into each beaker containing different temperature of

pure water. (0℃,25,50,75,100)

3. Covers with a cling film for each beaker to avoid evaporation.

4. Put the beakers into the incubator.

5. Wait for 20 minutes. (Use a stop watch)

6. Measure the weigh of each % change in mass of rice to determine how extreme

temperature affects to the rate of osmosis and the weight of dried rice.

7. Record the % change in mass

8. Make a graph for each temperature.

Data Collection and Processing:

Table 1: Change of Mass of Dried Rice in Different Extreme Temperatures

Temperature(℃) Change of Mass

(g)

Change of Mass

(g)

Change of Mass

(g)

1st trial 2nd trial 3rd trial

0 31.06 31.09 30.99

25 31.40 31.63 31.41

50 31.98 31.99 32.00

75 34.37 34.35 34.33

100 71.71 72.01 71.75

Table 1: shows that three trials of how much the mass of dry rice change according to

each different temperature after 20 minutes.

Table 2: % Change of Mass of Dried Rice in Different Extreme Temperatures

Temperature (℃) Change of Mass

(%)

1st trial

Change of Mass

(%)

2nd trial

Change of Mass

(%)

3rd trial

0 1.24 1.24 1.24

25 1.26 1.27 1.26

50 1.28 1.28 1.28

75 1.37 1.37 1.37

100 2.87 2.88 2.87

Table 2: shows that three trials of how much mass of dry rice changed in % according

to each different temperature after 20 minutes.

Sample Calculation:

Mean (average)

(1.24% + 1.24% + 1.24%) / 3 = 1.24%

(1.26% + 1.27% + 1.26%) / 3 = 1.263%

(1.28% + 1.28% + 1.28%) / 3 = 1.28%

Change of % Mass

31.06 g / 25 g = 1.24 %

31.4g / 25 g = 1.26%

31.98g / 25g = 1.28%

Graph 1: % Change of Mass of Dry Rice in Different Extreme Temperatures

Graph 1: shows that how many % changed in mass from 25g after 20 minutes in each

different extreme temperature of pure water. especially, the % change of mass of dry

rice increased at 75℃ to 100℃.

Graph 2: Error of % Change of Mass (Error Bar)

Graph 2: shows the error which is extending above and below the mean value to show

the range of the data.

Conclusion:

This investigation was to analyze the relationship between extreme temperature and the

rate of osmosis by absorption (% change in mass). Table 1 shows that how much grams

of dry rice changed from these of 25g after 20 minutes in different temperatures such as

0℃, 25℃,50℃,75℃ and 100℃. According to this table 1, table 2 shows how many %

of mass of dry rice changed after 20 minutes in 5 different temperatures of pure water.

As a result, dry rice in 0 to 50 ℃ of temperatures does not much change a % change of

mass. However, at 75 ℃, they suddenly got a mass a lot such as 1.28 % change of mass

to 1.37 %. The graph shows the % change of mass of dry rice and it obviously shows

the how much osmosis worked for dry rice. According to this result, as increase the

extreme temperature, % change in mass also increases. Especially, at 75 ℃ to 100 ℃,

the mass of rice in % increased rapidly. Therefore, the hypothesis was supported.

Evaluation:

When doing this investigation, even though I used incubator, it is hard to make constant

temperature while I was counting for 20 minutes. It sometimes decreasing temperature,

it is not kind of accurate result. In addition, when the weight was measured, I did not

take water completely and carefully so a lot of pure water was also measured when I

measure the weight of dry rice after 20 minutes. It was the cause of the fail result that

not only the weight of rice after osmosis occurs but also including the weight of water.

Therefore, the mass of change of dry rice might change few grams. For the next

investigation, it should be careful when making constant temperature by using incubator

accurately and the way of measuring should be more careful to find an accurate result.