U1L10 - The Scientific Method - WordPress.com · 2019-08-10 · 10.0 12.2 10.8 11.4 11.8 10.9 20.0...
Transcript of U1L10 - The Scientific Method - WordPress.com · 2019-08-10 · 10.0 12.2 10.8 11.4 11.8 10.9 20.0...
The Scientific Method
Purpose: What is your research question?
Hypothesis: What is your educated guess?educatedTemperature is a measure of molecular motion. Sugar dissolves more easily in hot water than in cold water because the molecules are moving more quickly. Therefore, as temperature increases, the amount of oxygen dissolved in the water should increase.
“What effect does temperature have on the concentration of dissolved oxygen in water?”
Temperature is a measure of molecular motion. Sugar dissolves more easily in hot water than in cold water because the molecules are moving more quickly. Therefore, as temperature increases, the amount of oxygen dissolved in the water should increase.
Temperature is a measure of molecular motion. Sugar dissolves more easily in hot water than in cold water because the molecules are moving more quickly. Therefore, as temperature increases, the amount of oxygen dissolved in the water should increase.
Purpose:Hypothesis: What is your educated guess?educated
independent variable
What you manipulate.
dependent variable
What you measure or calculate.
Procedure: Design a controlled experiment to test your hypothesis.
All other variables must be controlled.
controlled
“As temperature increases, the concentration of dissolved oxygen in water increases because of molecular motion.”
temperature“As temperature increases, the concentration of dissolved oxygen in water increases because of molecular motion.”
What relevant information (data) will you collect?
Procedure: Design a controlled experiment to test your hypothesis.
All other variables must be controlled.
controlled
Materials: Gather the necessary materials and safely perform the experiment.safely
Observations: relevant
ObservationsObservations:Observations What relevant information (data) will you collect?
Qualitative Quantitative
bluesmoothsmallerliquid
25.2 s40ºC
10.0 ml5.0 cm
relevant
ObservationsObservationsObservations: What relevant information (data) will you collect?
Quantitative observations are presented in clearly labelled tables. Make a table of all raw data collected.Qualitative observations are written below the raw data table.Often you will have to process the data before you display it in a graph. Show a sample calculation, then make a table of all processed data.
Quantitative observations are presented in clearly labelled tables. Make a table of all raw data collected.
relevant
Often you will have to process the data before you display it in a graph. Show a sample calculation; then make a table of all processed data.
Table 1: The concentration of dissolved oxygen gas in freshwater at various temperatures
Temperature (ºC ±0.5ºC )
Oxygen concentration in freshwater (ppm ±0.5 ppm)
Trial 1 Trial 2 Trial 3 Trial 4 Trial 5
1.0 14.4 13.8 14.1 14.3 13.610.0 12.2 10.8 11.4 11.8 10.920.0 9.9 9.9 10.2 9.8 10.330.0 9.3 9.1 8.5 9.0 9.040.0 7.8 8.0 7.9 8.3 8.050.0 7.7 7.4 7.0 7.3 6.9
The table is numbered There is a descriptive titleLabels at the top of columns, including unitsThe number of decimal points recorded agrees
Table 1: The concentration of dissolved oxygen gas in freshwater at various temperatures
Temperature (ºC ±0.5ºC )
Oxygen concentration in freshwater (ppm ±0.5 ppm)
Trial 1 Trial 2 Trial 3 Trial 4 Trial 5
1.0 14.4 13.8 14.1 14.3 13.610.0 12.2 10.8 11.4 11.8 10.920.0 9.9 9.9 10.2 9.8 10.330.0 9.3 9.1 8.5 9.0 9.040.0 7.8 8.0 7.9 8.3 8.050.0 7.7 7.4 7.0 7.3 6.9
Qualitative Observations: Small bubbles were observed at the bottom of the beaker for the 40℃ and 50℃ temperatures. A small amount of steam was produced by the 50℃ water.
Sample Calculation for the 1 ℃ trials:
Average oxygen concentration =The sum of all 5 trials
5
Temperature (ºC ±0.5ºC )
Oxygen concentration in freshwater (ppm ±0.5 ppm)
Trial 1 Trial 2 Trial 3 Trial 4 Trial 5
1.0 14.4 13.8 14.1 14.3 13.610.0 12.2 10.8 11.4 11.8 10.920.0 9.9 9.9 10.2 9.8 10.330.0 9.3 9.1 8.5 9.0 9.040.0 7.8 8.0 7.9 8.3 8.050.0 7.7 7.4 7.0 7.3 6.9
= 14.4 ppm+ 13.8 ppm+ 14.1 ppm + 14.3 ppm + 13.6 ppm
5
Sample Calculation for the 1 ℃ trials:
Average oxygen concentration =The sum of all 5 trials
5
= 14.0 ppm
=
Your calculator gives a value of 14.04, so
why have I recorded 14.0 ppm?
14.4 ppm+ 13.8 ppm+ 14.1 ppm + 14.3 ppm + 13.6 ppm
5
Table 2: The average dissolved oxygen concentration of freshwater at various temperatures
Temperature (ºC ±0.5ºC )
Average oxygen concentration in freshwater (ppm)
Standard deviation of average oxygen
concentration (±ppm)1.0 14.0 0.3
10.0 11.4 0.620.0 10.0 0.230.0 9.0 0.340.0 8.0 0.250.0 7.3 0.3
When multiple trials are performed (a minimum of 5) the standard deviation of the sample is a better measure of uncertainty than the uncertainty of the measuring device.
Sample Calculation for the 1 ℃ trials:
Average oxygen concentration =The sum of all 5 trials
5
= 14.0 ppm
= 14.4 ppm+ 13.8 ppm+ 14.1 ppm + 14.3 ppm + 13.6 ppm
5
Standard deviation (𝝈)is given by the following formula:
𝝈You could calculate it manually, but using Excel (or a calculator) is much easier.
Results: Display your processed data to illustrate the relationship between the variables.
In a controlled experiment, this usually means making a scatter plot graph. Draw a trend l ine to show the relationship between the variables. You can quantify this relationship by including the equation of the trend line and the R2 value.
In a controlled experiment, this usually means making a scatter plot graph. Draw a trend l ine to show the relationship between the variables. You can quantify this relationship by including the equation of the trend line and the R2 value.
In a controlled experiment, this usually means making a scatter plot graph. Draw a trend l ine to show the relationship between the variables. You can quantify this relationship by including the equation of the trend line and the R2 value.
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Water Temperature (ºC)0 10 20 30 40 50
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Figure 1. The effect of temperature on the average oxygen concentration of freshwater.
The figure is numbered
Figure 1. The effect of temperature on the average oxygen concentration of freshwater.
There is a descriptive title
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Figure 1. The effect of temperature on the average oxygen concentration of freshwater.
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Water Temperature (ºC)0 10 20 30 40 50
Independent variable on x-axis
Dependent variable on y-axis
Figure 1. The effect of temperature on the average oxygen concentration of freshwater.
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Figure 1. The effect of temperature on the average oxygen concentration of freshwater.
y= -0.13x + 12.2R2= 0.94
linear
Conclusion: Do your results support the hypothesis? Clearly state your conclusion. Use your graph to support your conclusion. Further, justify your conclusion with the theoretical mechanism involved (give references from the literature).
Discussion: What did you learn from your results?What do your results mean? How can the procedure be improved for the future? Are other research questions generated?
What do your results mean? How can the procedure be improved for the future? Are other research questions generated?
What do your results mean? How can the procedure be improved for the future? Are other research questions generated?
Clearly state your conclusion. Use your graph to support your conclusion. Further, justify your conclusion with the theoretical mechanism involved (give references from the literature).
Clearly state your conclusion. Use your graph to support your conclusion. Further, justify your conclusion with the theoretical mechanism involved (give references from the literature).
Clearly state your conclusion. Use your graph to support your conclusion. Further, justify your conclusion with the theoretical mechanism involved (give references from the literature).