Week 1 Midweek Assignment: Scientific Method Developing Hypotheses and Performing Experiments

Week 1 Midweek Assignment: Scientific Method

Developing Hypotheses and Performing Experiments

• Ice cube tray or 5 containers or cups for freezing liquids

• Timer

• 5 of any of the following liquids: tap water, salt water, sparkling water (without sugar), cola, rubbing alcohol, soap (hand or dish), juice, milk, syrup, cooking oil

• Freezer

• 5 plates, cups, or bowls

• Camera (can use webcam, smartphone, etc)

1. To make salt water, dissolve 1 teaspoon of salt into 1/8 cup of water. (You may have to heat the water to get the salt to fully dissolve).

1. Add each of the liquids listed above in the materials list to an ice cube tray or five containers. You only need one cube for each liquid. There should be the same amount of liquid in each cube or container.

1. Once you have filled the ice tray or containers, place them into the freezer.

1. Complete your hypothesis on the next page.

1. Each liquid needs to be completely frozen before you perform the next steps.

1. Empty your frozen cubes into your designated plates, cups, or bowls. Each cube should be in a different container.

1. Get a piece of paper and write your name and UAG student ID on it. Place the paper next to the cubes. Then take a picture of the frozen cubes with the paper clearly showing.

1. Start your timer and determine how long it takes for each of your cubes to melt.

1. Complete the Data Table below, insert or paste the picture you took of the frozen cubes, and answer the questions.

1. Then save the document and submit it.

1. Which substance do you think will melt the fastest? Why?

Based on my understanding of the properties of different liquids, I predict that the salt water will melt the fastest, followed by tap water, sparkling water, and cola. I believe that the salt water will melt the fastest because it has a lower freezing point than the other liquids due to the dissolved salt, which will lower the freezing point of the water. Tap water and sparkling water will likely melt at a similar rate, as they have similar chemical compositions and freezing points.

2. Which substance do you think will take the longest to melt? Why?

Cola will likely melt slower than the other liquids due to its high sugar content, which will increase its viscosity and make it more resistant to melting.

Insert the picture you took of your frozen cubes. Make sure the picture includes a piece of paper with your name and UAG student number.

1. Were your hypotheses correct? Explain.

My hypotheses were partially correct. I correctly predicted that salt water would melt the fastest, but I incorrectly predicted that tap water and sparkling water would melt at a similar rate. Instead, sparkling water melted slower than tap water. I also incorrectly predicted that cola would melt slower than the other liquids due to its high sugar content. Instead, cola melted at a similar rate to sparkling water.

1. Were there any results that surprised you? Why or why not?

The results that surprised me were the differences in melting times between sparkling water and cola. I expected cola to melt slower than sparkling water due to its higher viscosity, but the opposite was true. This may be due to other factors such as the specific brand of cola used or the concentration of sugar in the cola.

1. What would you need to do to determine if your results are reliable? Explain.

To determine if my results are reliable, I would need to repeat the experiment multiple times to account for any variability in the freezing and melting processes. I would also need to control for factors such as the temperature and humidity of the environment in which the cubes are placed, as well as the initial size and shape of the cubes. Additionally, I could use a more precise method of measuring the melting time, such as using a stopwatch or a thermometer to measure the temperature of the liquid.