Hypotheses and Trend Analysis

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# Hypotheses and Trend Analysis - PowerPoint PPT Presentation

Hypotheses and Trend Analysis. W rite a hypothesis (& science reason) for the following:. IV DV 1. temperature °C Solubility ( solute g/100 g of water) 2. mass (g) of box force (N) to overcome friction

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## Hypotheses and Trend Analysis

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### Hypotheses and Trend Analysis

Write a hypothesis (& science reason) for the following:

IV DV

• 1. temperature °C Solubility (solute g/100 g of water)
• 2. mass (g) of box force (N) to overcome friction
• 3. mentos candy foam volume (L)
• 4. acetic acid vol. (ml) carbon dioxide volume (L)
Hypothesis Wording for Quantity
• You make a prediction and then justify it with a science concept.
• If (your IV increases), then (your DV response to the change).
• Simply worded – not If (IV), then (IV change that will most affect DV).
• This will happen because … use the science to justify.
• Compare your hypothesis to the trend statement: As (your IV) increases, the (DV)… What’s the response to the change? State what the best fit line does.
What’s the correct hypothesis wording?
• IV = temperature (°C)
• DV = solubility (solute g/100 g of water)
• A. If 4 different temperatures are tested, then 50°C will have the best solubility.
• B. If the temperature increases, then the solubility of the solute (g/100 g of water) will increase.
• C. If the temperature changes, then the solubility of the solute (g/100 g of water) will be the most at the highest temperature.
What’s the correct hypothesis wording?
• IV = temperature (°C)
• DV = solubility (solute g/100 g of water)
• A. If 4 different temperatures are tested, then 50°C will have the best solubility.
• B. If the temperature increases, then the solubility of the solute (g/100 g of water) will increase. CORRECT
• C. If the temperature changes, then the solubility of the solute (g/100 g of water) will be the most at the highest temperature.
This will happen because…
• A. …the solute and solvent are both polar molecules and, therefore, compatible.
• B. …a solid solute dissolves more easily as temperature increases.
• C. …gas solubility in a liquid solvent decreases with temperature.
This will happen because…
• A. …the solute and solvent are both polar molecules and, therefore, compatible.
• B. …a solid solute dissolves more easily as temperature increases. CORRECT
• C. …gas solubility in a liquid solvent decreases with temperature.

### What’s the correct trend wording?

As the temperature increased, the solubility in 100 g of water increased.

As the solubility in 100 g of water increased, the temperature increased.

As the temperature decreased, the solubility in 100 g of water decreased.

As the solubility in 100 g of water decreased, the temperature decreased.

### What’s the correct trend wording?

As the temperature increased, the solubility in 100 g of water increased. CORRECT

As the solubility in 100 g of water increased, the temperature increased.

As the temperature decreased, the solubility in 100 g of water decreased.

As the solubility in 100 g of water decreased, the temperature decreased.

Don’t forget the data to support your trend statement.
• At 0°C the solubility was 18 g of solute/100 g of water, ……, and at 100°C the solubility was 49 g of solute/100 g of water. The overall % change from 0° to 100°C was 172%.*
• (Use all the data points – I am saving time)
• *[(49-18)÷18] x 100

### What’s the correct trend wording?

As the temperature increased, the solubility in 100 g of water increased.

As the temperature increase, nothing happened at low temperatures; then the solubility increased at higher temperatures.

None of the above.

### What’s the correct trend wording?

As the temperature increased, the solubility in 100 g of water increased.

As the temperature increase, nothing happened at low temperatures; then the solubility increased at higher temperatures.

None of the above. CORRECT As the temperature increased the solubility of NaCl in 100 g of water only changed from 38 grams to 38.5 grams. The temperature did not significantly affect the solubility.

### What’s the correct trend wording?Same data – scale is important.

There is no trend.

As the temperature increased, the solubility of NaCl in 100 g of water did not change.

### What’s the correct trend wording?Same data – scale is important.

There is no trend.

As the temperature increased, the solubility of NaCl in 100 g of water did not change. CORRECT

The graph is showing the same data as the previous graph, just with a different scale. The scale on the first graph was such that it skewed the data to look like there was a change when there really wasnt;.

Supporting Data
• At 0°C the solubility was 38 g of NaCl /100 g of water, ……, and at 50°C the solubility was 38.5 g /100 g of water. The percent change from 0° to 50°C was only 1.3%*.
• Again, I saved time, but you need to state all the data. Use % change to really show effect (or no effect).
• *[(38.5 – 38) ÷ 38] x 100
What’s the correct hypothesis wording?
• IV = mass (g) of box
• DV = force (N) to overcome friction
• A. If 4 different size boxes are tested, then smallest size will need the least amount of force.
• B. If box mass is tested, then the 20 g size will need the most force to overcome friction.
• C. If the box mass (g) increases, then the force (N) to overcome friction will increase.
What’s the correct hypothesis wording?
• IV = mass (g) of box
• DV = force (N) to overcome friction
• A. If 4 different size boxes are tested, then smallest size will need the least amount of force.
• B. If box mass is tested, then the 20 g size will need the most force to overcome friction.
• C. If the box mass (g) increases, then the force (N) to overcome friction will increase. CORRECT
This will happen because…
• A. …friction depends on the surface types. Friction increases with surface roughness.
• B. …friction depends on how hard two surfaces press together. Increasing mass of an object increases the force of an object resting on another surface.
This will happen because…
• A. …friction depends on the surface types. Friction increases with surface roughness.
• B. …friction depends on how hard two surfaces press together. Increasing mass of an object increases the force of an object resting on another surface. CORRECT
Correct Hypothesis Wording