Chemical equations - Science Revision Flashcards
What are the reactants of a chemical equation?
The substances at the start of a chemical reaction which react with each other .
What are the products of a chemical equation?
The substances formed by the chemical reaction.
What is the law of conservation of mass?
It states that the total mass of the reactants is the same as the total mass of the products.
How do you balance chemical equations?
Ensure there are equal numbers of each type of atom on both sides of the equation.
What is a synthesis reaction?
A reaction that combines simpler substances to form a new compound.
What is the basic equation for a synthesis reaction?
A + B —> AB
What is a decomposition reaction?
A reaction that breaks down a compound into simpler substances.
What is the basic equation for a decomoposition reaction?
AB —> A + B
What is the basic equation for a neutralisation reaction?
Acid + Base —> water + (metal) salt
What are the products of an acid + metal reaction?
Salt + hydrogen
What are the products of an acid + metal oxide reaction?
Metal salt + water
What are the products of an acid + metal carbonate reaction?
Metal salt + water + carbon dioxide
What is a precipitate?
An insoluble solid formed between 2 ionic solutions.
What is the solubility rule in reference to precipitation reactions?
If a product is insoluble, it will be precipitated out and be the precipitate.
What are the 2 precipitation reactions?
Single displacement reaction and Double displacement reaction.
What is a single displacement reaction?
When 1 reactant changes partners during the reaction.
What is the basic equation for a single displacement reaction?
AB + C —> AC + B
What is a double displacement reaction?
When 2 reactants change partners during a reaction.
What is the basic equation for a double displacement reaction?
AB(aq) +CD(aq) —> AD(s) + CB(aq)
What is an oxidation reaction?
When an element reacts with oxygen.
What are the products of a metal + oxygen reaction?
Metal oxide
What is an example of a non-metal and oxygen reaction?
2H(g) + 02(g) —> 2H20(g)
What are the combustion reactions of hydrocarbons?
Hydrocarbon + oxygen —> carbon dioxide + water
Hydrocarbon + limited oxygen —> carbon monoxide + water
What are examples of hydrocarbons?
Methane, ethane, propane, octane and diesel
What is a polymer?
A long chain molecule produced by joining small molecules called monomers together through polymerisation.
What are the 3 types of structures of a polymer?
Linear Polymers, Elastomers and Cross Linked polymers.
What are linear polymers?
Polymers in the form of long chains.
What are elastomers?
Polymers in the form of long chains that are connected every now and then with a small chain of atoms.
What are cross linked polymers?
Polymers of giant covalent lattices.
What are thermoplastic polymers?
Polymers that soften when heated gently and can be bent into a new shape.
What are thermosetting polymers?
Polymers that do not melt or change shape when heated.
What is a reaction rate?
How fast or slow a reaction occurs.
What is the collision theory?
For chemical reactions to occur, the atoms must collide with enough energy for the reaction to occur.
How do you increase the reaction rate?
You need to increase the number of collisions occurring.
How does increasing the surface area increase the reaction rate?
Breaking one of the reactants into smaller pieces allows more area for the collisions to occur.
How does increasing the concentration increase the reaction rate?
In a concentrated solution - there are more reactant particles.
How does increasing the temperature increase the reaction rate?
Particles in a hot temperature have more kinetic energy that causes the particles to collide more and at a faster speed.
How does stirring and mixing increase the reaction rate?
It removes the products of the reaction and replaces them with more particles of the reactants.
What are the states and symbols in a chemical reaction?
Gas = g
Liquid = l
Solid = s
Aqueous = aq
What does aqueous mean?
It dissolves in water
What is an independent variable?
The variable that stands alone and isn’t affected by other variables.
What is a dependant variable?
The variable being measured or tested - that changes because of the independent variable.
