NEW ZEALAND TARANAKI

Acids

My children have some simple ways to see if something is an acid...


Please read the important reminder below!

"Acids react with some substances by producing bubbles of gas (fizzing) and making them dissolve."

Here is one easy way to see if something is an acid..

HOW CHILDREN CAN TEST FOR ACIDS

Acids usually taste sour but we don't usually put things in our mouths unless its food (some acids are too dangerous!).

  1. Put 1/2 a teaspoon of Baking Soda into a cup.
  2. Add a little of your test liquid. If it makes bubbles and froth then the liquid is acting as an acid.

Now lets have some fun!

  • PREDICT: Ask your students "What will happen when I add Coca Cola to the Baking Powder?"
  • OBSERVE: Watch what happens in the first few seconds when your test liquid is added.
  • EXPLAIN: What does this show us? (seniors might like to consider the chemical reaction at work and ways to identify the gas given off)

Try water, milk, lemon juice, vinegar, rainwater and any other liquid an adult says is OK to test.

 

You can write down what you found out and try other liquids - but check with an adult first if its OK! Please read the important reminder below!

The bubbles are carbon dioxide gas created by a chemical reaction (a chemical reaction is a process in which one substance is chemically converted to another - all chemical reactions involve the formation or destruction of bonds between atoms).

Carbon dioxide is the same gas we breath out, and the gas plants need to make their own food. Carbon dioxide gas is used in fire extinguishers to put out fires.

You might be surprised to learn that your stomach contains a very powerful acid, called Hydrochloric Acid (HCl). Your body uses this to help dissolve and breakdown food into very small particles so your body can use it. See if you can find out why it doesn't dissolve you!

HOW CHEMISTS TEST FOR ACIDS

Another way to test liquids is to use Litmus Paper. BLUE coloured Litmus turns RED in acid.

Acids are dangerous chemicals because they can make things dissolve and fizz. There is another type of liquid called an alkali (or base) that is an acid opposite. It can react with things too and is dangerous.

We say alkali's (bases) are acid opposites because they make RED coloured litmus turn BLUE. Also if we mix an acid (harmful) and an alkali (harmful), we don't get a mixture that is twice as harmful, we get plain old salty water! They are opposites so cancel each other out to form salty water!

This process is called neutralisation. The salty water is not an acid, not an alkali, it is neutral.

An even better way to test liquids to see if they are acid, alkali or neutral is to use a colored dye called Universal Indicator. Universal Indicator is RED in acid, GREEN in neutral solutions, PURPLE in alkali.


IMPORTANT REMINDER....

Usually in science experiments the sense of taste is the one we don't use! Many chemicals look like water but are very poisonous if you accidently drink them.

NEVER TASTE CHEMICALS TO SEE WHAT THEY ARE!

ALWAYS ASK AN ADULT FOR HELP WHEN CARRYING OUT CHEMISTRY EXPERIMENTS.


FIND OUT MORE:-

  1. Make your own indicator, similar to Universal Indicator, using plant dyes.
  2. Learn about a special kind of acid you CAN eat! Make some sherbet using food acids.
  3. Build a rechargable battery that uses sulphuric acid.
  4. Tannic acid can be used to make a type of ink. Try it out here...
  5. Use the Baking Soda and vinegar again to build a model volcano.
  6. The interactive pages...identify these pieces of lab equipment
  7. The interactive pages...weird metals and gases hide in this Periodic Table
 

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