What is the pH of a neutral solution?

State the colour of Universal Indicator in a strongly acidic solution (pH 1).

What colour does Universal Indicator show at pH 7?

A student tests two solutions with Universal Indicator. Solution X turns yellow and Solution Y turns blue. State the approximate pH of each solution and identify which is acidic.

State the pH range of acidic solutions.

Solution A has pH 3. Solution B has pH 6. Which solution has a higher concentration of hydrogen ions, H⁺?

Solution P has pH 2. Solution Q has pH 5. (a) Which solution is more acidic? (b) How does the concentration of H⁺ ions compare between P and Q?

A solution has a pH of 1. Is this a strong or weak acid? Explain your answer.

Explain why adding water to a solution of pH 3 causes the pH to increase towards 7.

A student claims that a solution with pH 4 is twice as acidic as a solution with pH 8. Is this correct? Explain.

What colour does Universal Indicator turn in a strong alkali (pH 13)?

State the pH range of alkaline solutions.

Sodium hydroxide solution has a pH of 13. (a) What colour would Universal Indicator show? (b) What ion is responsible for the alkaline nature of this solution?

A student adds hydrochloric acid dropwise to sodium hydroxide solution (pH 13). Describe how the Universal Indicator colour and pH change as acid is added.

The table below shows Universal Indicator colours for five solutions A–E. A = Red | B = Yellow | C = Green | D = Blue | E = Purple (a) Which solution is neutral? [1] (b) Which solution is the most acidic? [1] (c) Which solution is the most alkaline? [1]