Using an universal indicator

Aim: To see the change in colour when the Ph level of a solution is changed.

Equipment: Large beaker, Magnetic stirrer, Magnetic hot-plate, Sodium Hydroxide, Sulfuric acid, universal indicator, water.

Method:
1. Put the large beaker onto the magnetic hot-plate and then add water into the Large Beaker until it is around 3/5 full.
2. Put the magnetic stirrer into the beaker.
3. Turn on the Magnetic hot-plate.
4. Put the universal indicator into the beaker.
5. Put in Sulfuric acid. By doing this, the colour should change to red.


6. Get the sodium hydroxide and put in a tiny amount of it into the beaker. Then wait for the magnetic stirrer and hot-plate to do its thing and mix the solution. This should change the colour to an orangish colour.







7. Keep adding small amounts of sodium hydroxide and record the change in colour.
8. Do this until the solution turns blue.

Safety:
Acid stuff, so be careful.


Result:
  
  

Evaluation:
Everything in this experiment went well. All except the fact that the magnetic stirrer was too big, so it occasionally stopped working. And, I didn't start taking photos from the beginning of the experiment.
Besides those two things, everything was perfect.

Discussion


What occurred during this experiment when acid was added:

During this stage of the experiment, dissociation occurred. At the beginning of the experiment, the colour of the solution was red. This was because there was a large number of hydrogen ions (Hᐩ) in the solution. The hydrogen ions (Hᐩ) are present in the solution because when the acid (sulfuric acid (H2SO4) was added to the water, the sulfuric acid dissolved in the water. When this happens, the sulfuric acid molecules (H2So4) dissociates (Break apart) into two hydrogen ions (2Hᐩ) and 4 Sulfur ions (SO4²¯).

What occurred during this experiment when a base was added.
In this stage of the experiment, dissociation and neutralization occurred. The base that we used (sodium hydroxide) (NaOH) was able to dissolve in water because it was an alkali. Similar to When sulfuric acid was added, when Sodium Hydroxide gets added, it dissolves, and then the molecules of the Sodium Hydroxide (NaOH) dissociates into a sodium ion (Naᐩ) and a hydroxide ion (OH¯). because the already existing hydrogen ions (Hᐩ) have a positive charge. When the negatively charged hydroxide ions (OH¯) are added, they become electrostatically attracted to each other. Because of this, the hydroxide ions bind to the hydrogen ions producing water (H2O). This is called neutralization.