HCl(aq) → H+(aq) + Cl-(aq)
Acidic solutions have pH values less than 7.
NaOH(aq) → Na+(aq) + OH-(aq)
Alkaline solutions have pH values greater than 7.
A neutral solution is neither acidic, nor alkaline. A neutral solution has a pH value of 7.
The pH scale measures the acidity or alkalinity of a solution. The pH of a solution can be measured using a pH probe, or estimated using universal indicator and a colour chart.
|Red litmus paper||Stays red||Stays red||Turns blue|
|Blue litmus paper||Turns red||Stays blue||Stays blue|
A few drops of universal indicator solution are added to solution X. The resulting mixture is yellow.
Estimate the pH of solution X, and state whether it is acidic, alkaline or neutral.
Solution X has a pH value of 5, and is acidic.