Chemical Energy

What is the test for carbon dioxide gas?

• relights a glowing splint

• lime water turns cloudy/ milky

• cobalt chloride paper changes colour from blue to pink

• lighted splint goes pop

What is the test for oxygen gas?

• relights a glowing splint

• lime water turns cloudy/ milky

• cobalt chloride paper changes colour from blue to pink

• lighted splint goes pop

What type of reaction is an acid reacting with an alkali?

• displacement

• neutralisation

• effervescence

• combustion

What type of reaction is burning a fuel?

• displacement

• neutralisation

• effervescence

• combustion

Which variable is being altered in the following reaction: small twigs burn easier than a log.

• concentration

• particle size

• temperature

Which variable is being altered when a blue flame on a Bunsen burner burns hotter than a yellow flame.

• concentration

• particle size

• temperature

Which variable is being changed when food lasts longer when stored in a fridge.

• concentration

• particle size

• catalyst

• temperature

What is a catalyst?

• A chemical substance that slows down a reaction

• A chemical substance that speeds up a reaction

• A transition metal

• A substance that speeds up a reaction and remains unchanged at the end of the reaction.

What is an enzyme?

• A chemical that can speed up a reaction

• A biological catalyst

• a chemical that slows down a reaction

• A transition metal

Enzymes only work ....

• in all types of conditions.

• at optimum pH, temperature and specific substrate

• only at the correct pH

• only at the correct temperature