Chemistry - Thermal décomposition Flashcards
What do chemical reactions involve
Re arranging atoms
Do chemical reactions always make new substances ?
Yes
Chemical reactions are easily reversable- true or false
False
Do chemical reactions involve energy transfers ?
Yes
What do physical changes include ?
Change of substance these reactions are reversable
Fuel + oxygen =>carbon dioxide + ………
Water
What are the things before the line called ?
They are called reactants
What are the things after the line ?
Products of the chemical reaction
Is methane a fuel ?
Yes
Do fuels burn in a chemical reaction ?
Yes
What is a fuel ?
It is a material that burns to transfer energy by heating
Name 4 fuels
Petrol,diesel,coal,hydrogen
What is burning also called ?
Combustion
What is methane a compound of ?
Carbon and hydrogen
Is making iron sulphide from iron + sulphur a chemical reaction
Yes
In a chemical reaction are the properties different ?
Yes the properties of the product are different to the properties of the reactant . A new substance is made
What is a decomposition reaction ?
This is wher compunds break down into simpler compounds or elements
What are the products of a thermal decomposition reaction of lead carbonate
Lead carbonated => lead oxide + carbon dioxide
What is a discrete variable
This is something that is described by words or by numbers that can only have a certain value such as a shoe size
What is a exothermic reaction ?
This is a reaction that gives out more heat energy to the surroundings than they take in so they feel hot and the tempreture rises
What is and endothermic reaction ?
This is where it takes in more heat from the surroundings than they give out so they feel cold and the tempreture falls
