Acid, Alkali, and Neutralisation

What are the properties of acids?

• Acids have a pH level higher than 7

• Acids have a pH level lower than 7, turn blue litmus paper red, and react with metals to produce hydrogen gas.

• Acids turn red litmus paper blue

• Acids do not react with metals

What are the properties of alkalis?

• Alkalis have a pH greater than 7, feel slippery to the touch, and can turn red litmus paper blue.

• Alkalis have a pH less than 7

• Alkalis can turn blue litmus paper red

• Alkalis feel rough to the touch

Name a commonly used indicator for acids.

• Litmus paper

• pH meter

• Red cabbage juice

• Thermometer

Name a commonly used indicator for alkalis.

• Methyl orange

• Litmus paper

• Bromothymol blue

• Phenolphthalein

What is a neutralisation reaction?

• A neutralisation reaction is a biological reaction between an acid and a base, resulting in the formation of a salt and oxygen.

• A neutralisation reaction is a chemical reaction between an acid and a base, resulting in the formation of a salt and water.

• A neutralisation reaction is a chemical reaction between two acids, resulting in the formation of a salt and water.

• A neutralisation reaction is a physical reaction between an acid and a base, resulting in the formation of a salt and sugar.

Explain the pH scale and its significance.

• Substances with a pH less than 7 are alkaline

• The significance of the pH scale is only relevant in industrial settings

• The pH scale measures the acidity or alkalinity of a substance on a scale of 0 to 14, with 7 being neutral. Substances with a pH less than 7 are acidic, while those with a pH greater than 7 are alkaline. The significance of the pH scale is that it helps determine the chemical properties of a substance and its potential effects on living organisms and the environment.

• The pH scale measures the temperature of a substance on a scale of 0 to 14

Give an example of a use of acids in everyday life.

• Household cleaning products

• Drinking water

• Toothpaste

• Cooking oil

Give an example of a use of alkalis in everyday life.

• Cooking oil

• Drinking water

• Toothpaste

• Household cleaning products

What happens when an acid and an alkali react?

• They explode and produce toxic fumes

• They form a new type of acid

• They create a solid precipitate

• They undergo a neutralization reaction, forming water and a salt.

How does the pH level change during a neutralisation reaction?

• The pH level becomes more basic

• The pH level tends to move closer to 7, becoming more neutral.

• The pH level remains unchanged

• The pH level becomes more acidic