Use indicators to identify whether a solution is acidic, basic,

Universal pH paper can indicate the exact pH value of a solution.

• True

• False

Answer explanation

Universal pH paper provides a range of colors corresponding to pH levels but does not indicate the exact pH value. Therefore, the statement is false.

Red litmus paper turns blue when it comes into contact with an acidic solution.

• True

• False

Answer explanation

Red litmus paper actually turns blue in the presence of a basic (alkaline) solution, not an acidic one. Therefore, the statement is false.

Blue litmus paper turns red when it comes into contact with a basic solution.

• True

• False

Answer explanation

Blue litmus paper actually turns red in acidic solutions, not basic ones. Therefore, the statement is false.

If a substance turns both red and blue litmus papers purple, it is neutral.

• True

• False

Answer explanation

The statement is false. A substance that turns both red and blue litmus papers purple is actually neutral, but it does not mean it is neutral if it only turns one type of litmus paper. Neutral substances do not change the color of either.

Red litmus paper will stay red in a neutral solution.

• True

• False

Answer explanation

Red litmus paper remains red in neutral solutions because it does not change color in the absence of acidic or basic conditions. Therefore, the statement is true.

What is the pH range of acids on the pH scale?

• 1–7

• 7–14

• 1–6

• 7–10

Answer explanation

Acids are defined as substances with a pH less than 7. The pH scale ranges from 0 to 14, where 1–7 indicates acidic solutions. Therefore, the correct range for acids is 1–7.

What color does blue litmus paper turn in an acidic solution?

• Red

• Blue

• Yellow

• It doesn't change

Answer explanation

In an acidic solution, blue litmus paper turns red. This is a standard test for acidity, where blue indicates a neutral or basic solution, and red indicates acidity.

Universal pH paper can measure:

• Only acidic solutions

• Only basic solutions

• Both acidic and basic solutions

• Neither acidic nor basic solutions

Answer explanation

Universal pH paper can measure both acidic and basic solutions by changing color according to the pH level. This allows it to indicate a wide range of pH values, making it versatile for various applications.

If the pH of a solution is 7, it is:

• Acidic

• Basic

• Neutral

• Strongly acidic

Answer explanation

A pH of 7 indicates a neutral solution, meaning it is neither acidic nor basic. Solutions with a pH less than 7 are acidic, while those with a pH greater than 7 are basic.

Describe what happens to red and blue litmus paper when dipped in a neutral solution.

Answer explanation

When dipped in a neutral solution, red litmus paper remains red and blue litmus paper remains blue, indicating that the solution is neither acidic nor basic.