Chemical Reactions and Balancing Equations

In a chemical reaction, the total mass of the products is different to the total mass of the reactants.

• True

• False

Pick the true statements.

• In chemical reactions, the atoms rearrange

• Some atoms disappear in chemical reactions

• Atoms can change their mass in chemical reactions

• There are the same numbers of atoms in the products as there are in the reactants

• Atoms are joined together differently in the reactants than they are in the products

Which option is not needed for a combustion reaction to occur?

• Fuel

• Heat

• Oxygen

• Light

Finish the word equation:

Iron + ______ > Iron oxide

What is produced when a hydrocarbon is burned?

Tick all that apply

• carbon dioxide

• oxygen

• water

• energy

Two solutions react in a beaker. The outside of the beaker begins to feel warm. Is this an endothermic or exothermic reaction?

• endothermic

• exothermic

A catalyst is a substance which speeds up a chemical reaction, without being changed or used up in the reaction itself.

• True

• False

On what side of a chemical equation are the reactants found?

• Left

• Right

Which of the equations below is correctly balanced?

• Na + H₂O > 2NaOH + H₂

• Fe + O₂ > FeO₂

Word Equation:

Sodium + Chlorine > Sodium chloride

Complete the balanced symbol equation:

2___ + Cl₂ > __ NaCl