Clouds from bottles: a twist!

Clouds from bottles: a twist!

Contributed by Alan Feria

Check out part 1 of “Cloud in a Bottle” by clicking the highlighted text.

Introduction 

Have you ever wondered why some days we have clouds, fog, rain, or a bright & sunny sky with no clouds at all? Well look no further than this at home demonstration that will explain to you why clouds form and how you can make your own cloud at home with simple ingredients that you probably already laying around in your home! ○ This experiment is a revamped version of “Cloud in a bottle” by Alan Feria 

Materials 

● Rubbing alcohol 50/70/91 % 

● 3 bottles of water preferably empty 

● Empty plate to discard unwanted liquids. 

● Sharpie marker for labeling 

Procedure 

1. First we will start by emptying the 3 water bottles if they aren’t empty already. Dispose of them properly by pouring the water into a plant or in the sink! 

2. Next what you will want to do is grab the 50% rubbing alcohol and pour about a tablespoon of the rubbing alcohol into one of the water bottles. 

3. Repeat this with the other two bottles but instead pour 70% and 91% respectively into each water bottle. 

4. Now this is where the marker comes in handy! Label each water bottle with the percent of alcohol you used so that we can keep track of which bottle has which alcohol. 5. Here is where the fun begins. You will want to twist and compress the water bottle so that there is less space inside the bottle. 

6. Once you feel that the bottle is super hard on the outside you can release the bottle cap by rapidly twisting it as if you were going to take it off. 

(Look at the video for a better understanding of steps 4-6!)

7. Repeat steps 5-6 for each bottle and record the amount of CLOUD and color of each cloud so that we can analyze them later! 

Concepts and Questions 

● Let’s start off by asking the question, “How does a cloud form” and how does this relate to our experiment? Clouds form when warm air rises into the atmosphere and when it gets high enough it cools and condenses. When warm is condensed, that warm air turns into small tiny water droplets and as more and more tiny water droplets come together they form what we call clouds. 

● Another thing that you may be asking yourself right now is why is there rubbing alcohol of different concentrations in each bottle as opposed to water or any other liquid. Well in simple words water is made of H2O which has 4 hydrogen bonds which are really strong and hold each other really close together while the rubbing alcohol has less than 4 hydrogen bonds per molecule and isn’t held together as strong. This makes it easier for the cloud to form! 

● So now that we know that rubbing alcohol is less strong than water let’s talk about why each concentration of rubbing alcohol is more or less effective. As we know, the concentration of each alcohol is just a ratio of pure rubbing alcohol to water. So 50% means there is 50% water and 50% rubbing alcohol. This applies to the other two types of rubbing alcohol that we used. 

Conclusions and Further Investigation 

Now that we know how clouds form and that rubbing alcohol in pure form breaks down easier than diluted rubbing alcohol, we can come to the conclusion of why the bottle formed a cloud and why the and why the bottle with the more pure form of rubbing alcohol was more effective at creating a cloud. To answer the first question, when we twisted and compressed the bottle the pressure and temperature went up quickly. Furthermore, when we release the bottle cap the temperature dropped quickly and that caused the warm air to condense rapidly and form what we see, A CLOUD! Onto the next question, the highest concentration of rubbing alcohol worked the best because it was in the most pure form and it ‘broke down’ easier and made the cloud more visible and easier for us to see. 

Citations 

https://scied.ucar.edu/learning-zone/clouds/how-clouds-form

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