Revision for Earth's Materials test

What is the main purpose of learning about the pH scale?

• To learn what the pH scale is and how to identify acids, alkalis, and neutral substances.

• To learn how to mix chemicals safely.

• To memorize the periodic table.

• To understand the structure of atoms.

If you wanted to find out whether a solution is acidic or alkaline, what would you use?

• An indicator

• A thermometer

• A magnet

• A filter paper

Based on the indicators you studied in class, which chemical is NOT an indicator?

• Phenolphthalein

• Blue litmus

• Red litmus

• Bromothymol blue

Based on the warning sign shown, what kind of safety hazard might be associated with acids and alkalis?

• They can cause burns or damage to skin.

• They can cause electrical shocks.

• They can cause loud noises.

• They can cause freezing.

What tool do we use to measure how acidic or alkaline a substance is?

• Thermometer

• Universal indicator

• Ruler

• Stopwatch

A student tests a liquid with universal indicator and it turns red. What can the student conclude about the liquid?

• It is a strong alkali

• It is neutral

• It is a strong acid

• It is a weak acid

Which of the following statements is true about acidic solutions?

• Acidic solutions have a pH greater than 7.

• Acidic solutions have a pH less than 7.

• Acidic solutions have a pH of exactly 7.

• Acidic solutions have no pH value.

Which of the following best describes what an indicator is used for in science?

• To measure temperature

• To show the pH of a solution

• To weigh substances

• To mix chemicals

What is the pH value of acids?

• Greater than 7

• Equal to 7

• Less than 7

• Exactly 10

What happens to the pH number of an acid or an alkali if water is added to it?

• The pH number stays the same

• The pH number moves closer to 7

• The pH number becomes negative

• The pH number becomes exactly 14