Chemistry Concepts for Grade 10

What is the pH range of acids?

• 7 to 14

• 8 to 14

• 0 to 7

• -1 to 0

Define a base according to the Arrhenius theory.

• A base is a substance that decreases the concentration of hydrogen ions (H+) in solution.

• A base is a substance that reacts with acids to form salts and water without affecting pH.

• A base is a substance that increases the concentration of carbon dioxide (CO2) in solution.

• A base is a substance that increases the concentration of hydroxide ions (OH-) in solution.

What is the chemical formula for hydrochloric acid?

• CO2

• HCl

• NaCl

• H2O

Describe the process of neutralization.

• Neutralization is the reaction between an acid and a base to produce water and a salt.

• Neutralization occurs when a base reacts with another base to form a gas.

• Neutralization is the reaction between a metal and a non-metal to produce electricity.

• Neutralization is the process of mixing two acids together.

What is a chemical reaction? Give an example.

• Photosynthesis: 6 CO2 + 6 H2O -> C6H12O6 + 6 O2

• Dissolving salt in water: NaCl -> Na+ + Cl-

• Rusting of iron: 4 Fe + 3 O2 -> 2 Fe2O3

• An example of a chemical reaction is the combustion of methane: CH4 + 2 O2 -> CO2 + 2 H2O.

List the signs that a chemical reaction has occurred.

• Formation of a solid layer

• Change in pH level

• Formation of a precipitate, Color change, Gas production, Temperature change, Emission of light

• Absence of odor

What are organic compounds?

• Organic compounds do not contain carbon.

• Organic compounds are carbon-containing substances that are essential for life.

• Inorganic compounds are always harmful to living organisms.

• Organic compounds are exclusively found in plants.

Name the simplest organic compound.

• Ethane

• Butane

• Methane

• Propane

What is the functional group of alcohols?

• -CHO (aldehyde group)

• -OH (hydroxyl group)

• -COOH (carboxyl group)

• -NH2 (amino group)

Explain the difference between saturated and unsaturated hydrocarbons.

• Saturated hydrocarbons are always liquid; unsaturated hydrocarbons are always solid.

• Saturated hydrocarbons contain only double bonds; unsaturated hydrocarbons have single bonds.

• Saturated hydrocarbons have fewer hydrogen atoms; unsaturated hydrocarbons have maximum hydrogen atoms.

• Saturated hydrocarbons have only single bonds and maximum hydrogen atoms; unsaturated hydrocarbons have double or triple bonds and fewer hydrogen atoms.