Today on Sci Guys acidbase indicators ltltIntro musicgtgt welcome to sci guys I’m Ryan and I’m Adam and today we’re going to be making an acidbase indicator using red cabbage. purple cabbage! Its called red cabbage. It’s purple. It’s name is red cabbage. purple cabbage. An acidbase indicator is a solution that changes color in the presence of an acid or base it can be a sudden change at a specific pH or a gradual change through many colours as the pH changes The equipment you need for this experiment includes a couple of glasses,.
A blender, coffee filters, and a funnel. We’re also going to need a few ingredients from the fridge and pantry. The items we need from the pantry are baking soda, vinegar, and distilled water. The ingredients we need from the fridge include lemon juice and a red cabbage. The last two items we need are ammonia and antacid taps. The safety equipment we’re gonna need today includes gloves, goggles, and an apron or lab coat to protect from spills or splashes. Also, since we’re dealing with hot water and sharp objects make sure you have adult supervision.
So the first step for our experiments is to add four cups of warm distilled water to our blender. Next we add two red cabbage leaves. Put the lid on securely. Holding the lid and give it a few pulses. ltltBlender Soundsgtgt The second step in our experiment is to take your coffee filter and your funnel and place the coffee filter inside the funnel. This will help prevent any small pieces of cabbage from getting into our solution. Place your funnel and coffee filter over top of another container and pour your blended solution.
The Sci Guys Science at Home SE2 EP4 Red Cabbage pH Indicator Acid Base Indicator
Through the coffee filter. Make sure to take any large pieces of cabbage out before you start this filtration process. The third step is to take your cabbage solution and pour it into several different glasses. Make sure to leave enough room for the rest of the liquid we will be adding to test for pH. The first solution we’re gonna test is ammonia. When ammonia is added it turns our solution a green colour. Which indicates that it’s a strong base. The second solution we’re gonna mix with the indicator is a little bit of.
Distilled water mixed with baking soda. The baking soda turns the indicator blue which tells us that it’s a weak base. The next solution we gonna add to our indicator is tap water. Tap water turns our solution a very slight blue color but it still looks like a shade of purple. This tells us that the tap water that we tested is slightly basic but close to neutral. The fourth item up for testing are antacid tabs. When we add a tablet or indicator carbon dioxide is produced and because carbon dioxide is acidic.
The colour changes to maroon. This is not the end for color change. Once our solution is done fizzing the other ingredients in our tablet cause the pH for our solution to shift slightly towards a neutral pH which changes the color slightly purple. Vinegar is our next solution that we’re gonna be adding to our indicator. When we add vinegar to our solution it turns a very bright red or pink colour. This colour change means that vinegar is acidic. Solution number six that will be testing is lemon juice. Lemon juice turns our solution a bright red or pink color.
Which means that lemon juice is also an acidic solution. Let’s look at this experiment a little closer. First let’s look at what pH is. pH is a scale that we use to measure acidity. The lower the number is on the scale the more acidic the solution is. Water is a neutral solution and has a pH of around seven. Vinegar which is one of the most common household acids has a pH of 2.2. pH is determined by the number of hydrogen and or hydroxide molecules a solution has. One of the ways that scientists.
Determine the acidity of an unknown solution is with a pH indicator. There are many different kinds of indicators but what they all have in common is they all change colour based on the pH of a solution. The natural pigment present in red cabbage is called anthocyanin and is an example up an indicator. These indicators show the pH of a solution by changing colour. Now the colour of an object that we see depends on the shape for the molecules the object is made of. White light contains every colour in the rainbow.
And each colour has a different wavelength. Molecules of different shapes reflect and absorb different wavelengths of light. The wavelength of light that reflects off a molecule is the one that reaches our eyes and that determines what colour we see while all other wavelengths are simply absorbed. When we add an acid to our red cabbage solution. We flood it with hydrogen molecules which causes the indicator to change shape and reflect red wavelengths making the solution look red. If we add a strong base there is instead a high amount of hydroxide molecules causing the shape the indicator.
To change colour and reflect green or yellow light. Solutions that are only slightly acidic or basic will change the colour the indicator two shades of maroon or blue respectively. The really neat thing about a cabbage indicator is that the shape of our molecule is reversible so we alternate adding acids and bases the colour can continue to change back and forth provided you don’t add a strong solution such as bleach that will eventually destroy the pigment completely. well that’s it for acidbase indicators I hope you enjoyed it.
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