Chemical Reactions Quiz

Which of the following is NOT evidence of a chemical change?

• Change in color

• Formation of a gas

• Change in temperature

• Change in shape

• The number of molecules

• The number of atoms

• The number of H₂ molecules in the equation

• The subscript indicating the phase of matter

According to the law of conservation of matter, in a chemical reaction,

• Matter is created.

• Matter is destroyed.

• The total mass of the reactants equals the total mass of the products.

• The total mass of the reactants is greater than the total mass of the products.

Which of the following is a physical change?

• Burning wood

• Rusting of iron

• Dissolving salt in water

• Milk souring

What is the main difference between a chemical change and a physical change?

• A chemical change can be easily reversed, while a physical change cannot.

• A physical change alters the chemical composition, while a chemical change does not.

• A chemical change results in the formation of one or more new substances, while a physical change does not.

• A physical change always results in a change of state, while a chemical change does not.

Which of the following is an example of a chemical change?

• Boiling water

• Melting ice

• Frying an egg

• Cutting paper

Which of the following is NOT a sign of a chemical reaction?

• Formation of a precipitate

• Change in color

• Boiling

• Emission of light

The law of conservation of matter applies to which types of changes?

• Only physical changes

• Only chemical changes

• Both physical and chemical changes

• Neither physical nor chemical changes

What happens to the atoms in a chemical reaction?

• They are destroyed and new atoms are formed.

• They are rearranged to form new substances.

• They remain unchanged but are transferred from one substance to another.

• They are converted into energy.

Which of the following processes is a physical change?

• Fermentation of grape juice into wine

• Dissolving sugar in water

• Cooking an egg

• Burning gasoline