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How to Make Litmus Paper: A Complete Step by Step Guide

Updated on February 10, 2017
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Susan is a science geek, and if that wasn't enough, she gets all nerdy over technology too. She is also a writer too.

Introduction

Learn how to make litmus paper with this step by step guide!

Welcome! In this guide, we will be teaching you how to make your very own litmus paper and do other experiments. It's fun and easy to make, and it can be made using household ingredients. Children would love to make this, and it really looks magical.

Lemons can be used to test your litmus paper. Litmus paper will turn red as lemons are acidic.
Lemons can be used to test your litmus paper. Litmus paper will turn red as lemons are acidic. | Source

What Is Litmus Paper?

Litmus paper is an indicator used to test whether a substance is acidic or basic. You simply dip the paper in your substance, and it will change colour depending on whether it is acidic or basic. It will go red in an acid and blue in a base. It is a lot of fun to make and is very easy. The kids would love to get stuck in with this project!

Materials Needed

  • Blotting Paper, Cut into strips
  • 2 cups Red Cabbage, Chopped
  • 10ml Lemon Juice
  • 10ml Vinegar
  • Soap

Instructions

  1. Boil your red cabbage until the water it is boiling in is a red-purple colour from the cabbage. Strain the red cabbage from the solution.
  2. Cut your blotting paper into small strips.
  3. Put your blotting paper strips into the solution and leave them there to soak.
  4. Take them out and leave to dry.
  5. Your litmus strips are now ready to use!

Where to Buy Blotting Paper

Update:

An increasing number of people have told me that they couldn't try this experiment out as they couldn't find any blotting paper in the shops. To all of you out there, the very same happened to me and I'm sorry I didn't address this issue earlier. If you cannot find any blotting paper in the shops, you can buy blotting paper on Amazon. Check it out!

Litmus paper dipped in acid turns red (right of strip) and dipped in base turns blue (left of strip).
Litmus paper dipped in acid turns red (right of strip) and dipped in base turns blue (left of strip).

Experiment One

Experiment Time!

Now that you have your litmus paper strips, it is now time to experiment.

  • Dip a strip of litmus paper into the substance.
  • If it turns red, that substance is an acid.
  • If it turns blue, that substance is a base.
  • If it stays the same, that substance is neutral.

Example:

Let's take lemon juice for example. Dip a litmus paper strip into the lemon juice. It will turn red as the lemon juice is acidic.

  • Try all the substances below.They will give you some ideas on what to test. You can print the table out and tick off whether each substance is acidic, basic or neutral.

Use Your Litmus Paper to Test These Substances

Substance
Acidic?
Basic?
Neutral?
Vinegar
 
 
 
Milk of Magnesia
 
 
 
Washing Up Liquid
 
 
 
Fizzy Drinks
 
 
 
Sour milk
 
 
 
Toothpaste
 
 
 
Soapy Water
 
 
 
Lemon Juice
 
 
 
Baking Soda Solution
 
 
 
Black Coffee
 
 
 
Tomato Juice
 
 
 
Orange Juice
 
 
 
It's raining!
It's raining! | Source

Testing Rainwater

Rainwater is generally slightly acidic. This occurs from acid rain. The carbon dioxide that is pumped from the factories goes out into the air and mingles with the clouds. This causes carbonic acid. Acid rain is very damaging. It can damage limestone monuments and kill fish in the rivers. You can test whether the rainwater in your area is slightly acidic. Here's how:

  1. Make a rain gauge out of a bottle or glass jar. Place it outside away from any trees or shelter that may prevent the rain to go in.
  2. Place a funnel over your rain gauge.
  3. Leave the rain to fill it.
  4. Dip your strips of litmus into the rainwater.

Red cabbage indicator
Red cabbage indicator | Source

How Does It Work?

The red cabbage you used can be used as pH indicator. It is red or pink in acids (pH < 7), purple in neutral solutions and ranges from blue to green to yellow in alkaline solutions (pH > 7).

The pH Scale

Knowing whether a substance is acidic or basic is only the first step. Scientists in the laboratory need to know how strong/weak an acid or base really is. Sodium Hydroxide is a very strong base and can burn your skin if you come in contact with it. Therefore, there is a scale called the pH scale which ranges from 1-14.

  • Very strong Acids are around 1-2 on the pH Scale.
  • Weaker acids are 3-6 on the pH scale.
  • Neutral (neither acidic or basic) are 7
  • Weak bases are 8-9 on the pH scale
  • Very strong bases are 10-12 on the pH scale

To determine how strong/weak an acid or base is and where it is on the pH scale, scientists use universal indicator paper which can be seen on the top right. You dip the paper into the substance of your choice and it will change colour. You can then determine how strong an acid or base is by judging the colour of the paper to the colours on the pH scale. See picture at top.

Experiment Two

Neutralisation

There are ways to make a substance neutral (having a pH the same as water). Neutralisation is done when the same amount of an acid is added to a base.

Real-Life Applications:

There are many real life applications to this concept. Let's say that a truck containing a strong acid overturned and the acid spilled everywhere. It would destroy and burn everything. The emergency team will add a base such as lime to the acid. The acid will be neutralised making it virtually harmless. Or let's say you had indigestion. Indigestion is caused by strong acids in your stomach. You might take indigestion tablets to relieve the pain.The indigestion tablets are bases. So, these bases neutralise the acids making them virtually harmless.

Instructions

  1. Add a teaspoon of washing-up liquid into a cup or container.
  2. Add the same amount of vinegar into the washing-up liquid.
  3. This way the two substances become neutralised.
  4. Dip a strip of litmus paper into it. If the strip stays the same colour, it is proven that the two substances have been neutralised. A great way of showing this concept in action.

Acid-Base Titration
Acid-Base Titration | Source

Acid-Base Titrations

  • The topic of neutralisation leads onto another topic. When you neutralise an exact amount of acid with a base, a salt + water is formed. This is known as an acid-base titration.
  • The acid goes on top, and the base goes on the bottom.
  • An indicator such as methyl orange or litmus is put into the base. It turns yellow. Then the acid is put into the base drop by drop until the methyl orange indicator turns orange.
  • When the indicator turns orange, you can be sure that the two substances are neutralised. The solution is poured into an evaporating dish and is evaporated off.
  • It is noticed that a salt is left.

Would you like to create litmus strips?

See results

© 2013 Susan W

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    • susi10 profile image
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      Susan W 4 years ago from The British Isles, Europe

      Please share your thoughts on this hub!!

    • RTalloni profile image

      RTalloni 4 years ago from the short journey

      Interesting to learn about making litmus paper and to see encouragement to enjoy science.

    • susi10 profile image
      Author

      Susan W 4 years ago from The British Isles, Europe

      Thanks for stopping by RTalloni! I am so glad that you liked my hub. I appreciate your feedback.

    • melbel profile image

      Melanie Shebel 4 years ago from New Buffalo, Michigan

      I learned about the red cabbage thing in chemistry last semester and I was just intrigued and baffled by it. I love how your hub goes step by step into how to make litmus paper instead of just saying, "hey, red cabbage does the trick."

      I'm definitely going to have to play around with making litmus paper. Thanks for the awesome hub!

    • susi10 profile image
      Author

      Susan W 4 years ago from The British Isles, Europe

      Thanks for reading, melbel and I am so happy that you liked it! I am sure the litmus paper will turn out perfectly for you.

    • queerlyobscure profile image

      Cecil Wilde 4 years ago from Melbourne, Australia

      This would be so much fun to use to teach kids some basic chemistry principles about acids and bases. Now to find some kids I can play with! Uh, I mean 'teach' ;)

    • susi10 profile image
      Author

      Susan W 4 years ago from The British Isles, Europe

      Hi queerlyobscure and welcome to HubPages!

      Thank you for reading this hub about litmus paper. I am so glad you liked it! Yes, it would be a lot of fun to teach kids some basic chemistry principles, especially as the experiment is so fun to do and has great results.

    • profile image

      William 3 years ago

      The rain in my country (South Africa) is Ph 7, electronically tested.

      How long must one wait before seeing blue, if Ph is above 7?

      I have found that the 'blue' is only a hue and not distinctly blue after waiting for about 30 seconds. I am beginning to think that my chemist bought Litmus is old.

      Further the paper is already red, so it does not change colour in an acid solution,.it just looks wet red.

      I have also found that nothing happens in distilled water even if it is acid or alkaline.

      Help me please?

    • susi10 profile image
      Author

      Susan W 3 years ago from The British Isles, Europe

      Hi William,

      Thanks for reading this, sorry that it took me so long to reply! Using litmus paper, it should take you a couple of seconds until you see a colour change. The hue/colour of the blue should vary between different types of litmus paper that you buy, I suggest buying new litmus paper if you don't see any effects on the litmus paper that you are using.

      In relation to testing acids, I recommend that you use blue litmus paper and if the substance you are testing is an acid, the blue will change to red.

      Distilled water has a pH of 7 so it is neutral. Neutral substances do not have any effect on litmus paper so that is why you have not seen any colour changes. For more accuracy, try using Universal Indicator Paper or a pH meter.

      Thank you for your questions and I am pleased to have helped!

    • FlourishAnyway profile image

      FlourishAnyway 3 years ago from USA

      This is a wonderful way to engage a budding young scientist on a holiday break while school is not in session. I have a middle schooler that I am going to use this with, all in the name of fun. We are continually trying to interest her in the sciences. Shared, pinned and voted up +++.

    • Frank Atanacio profile image

      Frank Atanacio 3 years ago from Shelton

      this will make a good science project great hub

    • ologsinquito profile image

      ologsinquito 3 years ago from USA

      This is very useful. I voted up and I'm pinning it on my Things You Really Need to Know board.

    • asfarasyouknow profile image

      Red Solomon 3 years ago from Midwest

      Honestly this is very descriptive in the terms of science and manufacturing. However, it would be nice to have some examples or other reasons why and how one can use these strips in the household for everyday causes. Even though this is very helpful for those who need it; It does not seem practical past the experimental purpose. If I was to do this experiment with my children, what practical applications would it be helpful for? Thanks a lot, you have really sparked my interest.

    • susi10 profile image
      Author

      Susan W 3 years ago from The British Isles, Europe

      Hi Flourish Anyway,

      Thanks for dropping by and for your great comments. This experiment will definitely encourage your middle schooler into science, no doubt. Some interesting kitchen science experiments are the best way to get children involved in science. There are countless other experiments which you can show her such as growing crystals. I always loved growing crystals! Now that you mention it, I think I will write more kitchen science hubs with more interesting experiments.

      Thanks for the pin and the vote up, Flourish Anyway!

    • susi10 profile image
      Author

      Susan W 3 years ago from The British Isles, Europe

      Hi Frank,

      Thanks for the read and for the kind comment, I appreciate your visit. Yes, this would be a good science project to do, and children can learn about acids and bases and become interested in science.

    • susi10 profile image
      Author

      Susan W 3 years ago from The British Isles, Europe

      Hi ologsinquito!

      Thanks so much for the pin, you have really brightened my day with that! I'm glad you have found this useful, it will always be useful to know a bit of science!

    • susi10 profile image
      Author

      Susan W 3 years ago from The British Isles, Europe

      Hi asfarasyouknow,

      Thank you for reading this and for your interesting question. Yes, I see your point, this may not seem to be practical past experimental purpose but I think that there is practicality with this experiment.

      This experiment is fairly simple in contrast to the big chapter of pH and acids and bases. Acids and bases are quite an important part of our lives. The pH of our bodies signalises our health and how healthy our body is. Slightly more alkaline blood signalises health whilst an overall acidic body may signalise a less healthy metabolism. As you can see, knowing the pH of our bodies internal systems is essential to our wellbeing. So, this experiment is a stepping stone to measuring pH and acidity and alkalinity.

      If you were to do this experiment with your kids, they would learn about chemistry in general (which is constantly shaping the medical world), the pH of substances and they would learn about the world of science. pH plays a major role in chemistry and chemistry is constantly shaping our world with advances in medicine, materials and health.

      I hope this answers your question, if you need clarification or if you have more questions, just let me know.

    • asfarasyouknow profile image

      Red Solomon 3 years ago from Midwest

      This is definitely not a mundane project and in no way was my comment to negate the potency of your article. Actually, I may not even be educated enough in applied chemistry to find a common use for these strips. pH has never intrigued my attention until you shared this knowledge and have inspired me to research more information. Thank you for your response.

    • profile image

      achapin3 3 years ago

      This is the kind of old school medicine techinques I have been interested in for years. I am a medical professional and I always think, what if i had to treat my friends and family if society collapsed? What if we no longer had hospitals? It is these types of things we would need to know. You would have to have home grown tecniques. Thank you for this article.

    • susi10 profile image
      Author

      Susan W 3 years ago from The British Isles, Europe

      Thank you for sharing your thoughts and for commenting, always appreciated. Yes, learning methods like this are a great way to be able to rely on your own medical techniques if you could not visit a doctor.

    • tirelesstraveler profile image

      Judy Specht 2 years ago from California

      Testing the water for balancing acid in a swimming pool mandates you know the how ph and neutralization work . This is a very nice, simple, easy to follow explanation.

    • susi10 profile image
      Author

      Susan W 2 years ago from The British Isles, Europe

      tirelesstraveler - Thanks for the great comments! I agree, checking the pH of a swimming pool is vital. It could get pretty ugly then, lol. :-)

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