Science Revision Quiz

The products when an acid reacts with a carbonate are:

• Salt and water

• Salt and Hydrogen

• Salt water and oxygen

• Salt, water and carbon dioxide

Which of these chemical reactions observes the law of conservation of mass?

• H₂ + O₂ → H₂O

• 2Na + Cl₂ → 2NaCl

• NaOH + HCl → NaCl + H₂O

• Both be and c are correct

In a chemical reaction:

• bonds are broken and atoms are rearranged to make new substances.

• the original substances disappear and are replaced by new substances

• the original substances remain but are joined by new substances

• the atoms of the original substances break down and new atoms are made

What does an increase in temperature signal in a reaction?

• It is an exothermic reaction

• It has undergone a chemical change

• It involves dissolving

• Both and a and b are correct

When hydrogen reacts with oxygen water is formed.

What are the reactants?

• Hydrogen only

• Water and hydrogen

• hydrogen and oxygen

• oxygen only

When hydrogen reacts with oxygen, water is formed.

Which is the correct word equation for this reaction?

• Hydrogen + oxygen → water

• Oxygen + water → hydrogen

• Hydrogen → water + oxygen

• Hydrogen + oxygen = water

The law of conservation of mass states that:

• atoms must stay the same in the reactants and products

• matter and energy can neither be created nor destroyed

• the reactants and products can never change in a chemical reaction

• matter can be created in a chemical reaction

What is a spontaneous reaction?

• A reaction that needs energy to start

• A reaction that happens without any reactants

• A reaction that does not produce any products

• A reaction that requires no energy to start

The energy input to start a reaction is called the:

• thermal energy

• activation energy

• heat energy

• electrical energy

What type of reaction is being shown in this image: