Year 8 Chemical Reactions

Which of the following processes is an example of a chemical reaction?

• A litre of water boils dry in a saucepan
• A mist forms when you breathe onto cold glass
• Sodium reacting with oxygen forming oxide
• Ice melts when held in the palm of your hand

Which of the following is NOT evidence of a chemical reaction taking place?

• Change in colour
• Heat produced
• Bubbles created
• Solid becoming liquid

In the chemical reaction : sodium + chlorine -> sodium chloride, the products are

• sodium
• chlorine
• sodium chloride
• sodium and chlorine

2MgO -> 2Mg + O2 is an example of what type of reaction?

• Combustion
• Breaking down
• Combination
• Precipitation

Which of the following is NOT a state of matter used in a chemical equation?

• (s)
• (aq)
• (o)
• (g)

Which of the following would you expect to be acidic?

• Vinegar
• Soap
• Baking soda
• Bleach

A basic substance would have a pH of 

• 7
• more than 7
• less than 7
• 0

2H2 + O2 -> 2H2O is an example of a 

• Word equation
• Particle diagram
• Chemical equation
• Addition equation

Which of the following will slow down a reaction rate?

• Decreasing temperature
• Adding a catalyst
• Increasing concentration
• Increasing surface area

A biological catalyst is called...

• An acid
• An enzyme
• A bacteria
• A base