X is hydrochloric acid solution, Z is sodium chloride solution and Y is sodium hydroxide solution.
Explanation:
I will try be as detailed as possible.
Litmus paper:
-Short summary: Bases will turn blue and red litmus papers to blue and acids will turn blue and red litmus papers to pink while the pink will remain pink.(Simple Mnemonic: You can say B from base turns blue litmus blue and the others are the opposite).
-Also, neutral solutions will have not cause any color change on litmus papers. This is because litmus papers have a color change in the presence of H+ from acids and Oh- from bases. So, blue litmus paper remains blue and red litmus paper remains pink.
-Hydrochloric acid solution is a strong monoprotic acid because it fully dissociates to produces H+ ions. Therefore, in the presence of blue and pink litmus papers it will turn the blue to pink and the pink will remain pink.
-Sodium chloride solution is a neutral solution because it dissociates to Na+ and Cl- which do not play a role in the color change.
-Sodium hydroxide solution is a strong monoprotic base hence it fully dissociates to produce OH- no wonder the high pH value.
pH value:
-Acids have a pH value is <7 while pH of neutral solutions is 7 and basic solutions is >7.
-So from this analogy we can say that hydrochloric acid solution is 2,sodium chloride solution is 7 and sodium hydroxide solution is 10.
Universal indicator:
-A universal indicator gives a more precise data as compared to litmus because it not only identifies the type of the solution (acidic, basic or neutral) it also tells us the strength of the solution by comparing the color of the solution when the universal indicator is added against the pH universal indicator scale.
-Unfortunately ,the colors are quite a lot and I cannot type all of them but you could search for 'pH universal indicator scale' to clearly see the whole thing.
-In the scale, you can see that after addition of the universal indicator, sodium chloride solution neutral solutions (pH7) will give a green color, hydrochloric acid solution (pH=2) which is a strong acidic solution will give a red color and sodium hydroxide solution (pH=10) which is a strong base will give a blue solution.
Reaction with Magnesium:
-I'd like to recommend also that you search for 'metal reactivity' so that you can be able to see the trend .
-A highly reactive metal can displace a low reactive metal but a low reactive metal cannot displace a high reactive metal under normal conditions.
-So, for sodium hydroxide and sodium chloride solutions with magnesium ,magnesium cannot displace sodium because sodium is one of the most reactive metals therefore there will be no change.
-For hydrochloric acid solution, the reaction will take place because Magnesium is more reactive than hydrogen thus can be able to displace hydrogen ions and form Magnesium chloride solution.
~I hope this will help. All the best:)
