Reactions Flashcards
Does the mass change in a chemical reaction
In a chemical reaction no atoms are made or lost just re-arranged so the mass will stay the same
Name 2 things that can change during a chemical reaction
Temperature and colour
Combustion meaning
Burning in oxygen
What three things are needed for combustion
Fuel
Heat
Oxygen
What does oxidation mean
When an object reacts and combines with oxygen it is called an oxidation reaction for eg combustion and rusting
What is thermal decomposition
Thermal decomposition is when a substance breaks down into at least two other substances when heated.
What is a hydrocarbon
fuels containing only hydrogen and carbon.
What is the difference between chemical and physical changes
Chemical changes make new substances whereas physical changes usually involve a change of state
What is a catalyst
Catalysts help speed up the rate of reaction
What is a fuel
A fuel is a material that releases energy in the form of heat such as coal , oil and gas
What is the equation for combustion / burning
fuel+ oxygen ——-> carbon dioxide + water
What are the products of decomposition
Calcium carbonate calcium oxide and carbon dioxide
What is the law of conservation of mass
Mass of reactants = mass of products
Difference between exothermic and endothermic reactions
Exothermic reactions so an increase in temperature eg burning fuels
Endothermic reactions so a decrease in temperature eg sports ice packs
Gas test carbon dioxide
Turns limewater milky
