Combining Solutions of Ionic Compounds Lab Report

Combining Solutions of Ionic Compounds

Purpose:  To find out how the properties of acids and bases be used to classify solutions.

Materials: -4x6 spot plate

-Masking tape

-Solutions A,B,C, and D (some are corrosive)

-4 Pieces of Mg ribbon

-4 Pieces of red litmus paper

-4 Pieces of blue litmus paper

-Bromothymol blue solution

-Indigo carmine solution

-Methyl orange solution 

          

Procedure:  The procedure used was from the BC Science 10 textbook on page 230

Results:

Mg Ribbon	Red Litmus	Blue Ribbon	Bromothymol Blue	Indigo Carmine	Methyl Orange	Unknown
Began to bubble somewhat quickly, bubbles formed on the bottom.	Red paper, but the solution looks blue	Nothing	The solution turned yellow	The solution turned blue	The solution turned red	A
Nothing	The paper was blue	Nothing	The solution turned royal blue	The solution turned dark green	The solution turned yellow orange	B
A few small bubbles	The paper was red	Nothing	The solution turned green	The solution turned blue	The solution turned yellow orange	C
A few small bubbles	The paper was blue	Nothing	The solution turned light blue	The solution turned  blue	The solution turned yellow orange	D

Discussion

Analyze:

From most acidic to most basic I think is A,C,B,D.  I am not certain as I really am not confident with my results. Even with this, I believe that the neutral solution was C.  I believe that the most alkaline solution was solution B. My reasoning is that it was the only solution to not react at all with the Mg ribbon and it reacted with the liquid indicators as well. The ribbon was useful for testing the pH as acids would react with it to produce a salt and hydrogen gas. The gas then was able to bubble in the solution.

Conclude and Apply:

If there was a pH of 3 in a solution, the indicators would be red. If there was a pH of 10, the indicators would be blue. If I needed 3 tests to see if a sample was acidic, neutral, or basic, I would use red Litmus paper, blue litmus paper, and an alkaline earth metal. My reasoning is pretty obvious for the litmus paper as it would give a pretty instant reading. The metal would be good confirmation if the sample was acidic as it would react. For the colour of the Roccella tincoria being dipped in vinegar, my educated guess would be that it turns red. This is because vinegar is acidic. To find out the colour of seawater with Bromothymol blue added to it, I needed to find out the pH of seawater. I learned that is a little bit basic. And when Bromothymol blue reacts with bases, you get a dark blue colour.

Conclusion

This experiment was interesting. I think that the results we got however were off. They were different than the other group we worked with. However, we were able to clearly identify the acid thanks to the liquid indicators, litmus, and the magnesium.  Another problem we had was the beakers with solution were not properly labelled, so we weren’t 100% sure which solutions were A,B,C, and D.