Science Chem Reactions

Metallic Bonding

between 2 metals

Ionic Bonding

between 2 metal and non metal

Covalent

between 2 non metals

Naming covalent bonds

Using number prefixes to say how many of each atom

Naming Ionic

Drop the end and add ide when a non-metal becomes an ion

exothermic reactions

chemical reactions that release energy into the surroundings

endothermic reactions

chemical reactions that absorb energy from their surroundings

Polyatomic ions

an ion composed of two or more atoms

Energy Profile Diagrams

a diagram of different energies involved in a reaction

Activation energy

the energy required to break the bonds between the atoms to start a reaction

Activation Energy Formula

E2-E1

Enthalpy

The change of energy between the reactants and products

Enthalpy Formula

E3-E1

4 factors that affect ROR

concentration temperature surface area catalyst

Precipitation

the formation of a solid in a solution during a chemical reaction

Categories of Reactions

Synthesis Decomposition Combustion Neutralisation Precipitation Displacement

Catalysts

a substance that lowers the activation energy required for a reaction to occur

precipitation reaction

Dance partners swap, The non-metal or negative Ion groups swap “partners”

AB + CD -> AD + CB

2 products - AD + CB – need to determine if the products stay in solution or if they form a material that is insoluble – precipitate (solid)

LHS and RHS in displacement

Metals in solution and Metals by itself

Reaction occurs Displacement General Form

A+BC=B+AC

No Reaction Displacement General Form

A+BC= No Reaction

LHS>RHS

reaction will occur

LHS<RHS

no reaction will occur

Displacement reactions

the a possibility that a negative ion will swap with the metal.

Combustion Reactions

a reaction where reaction when a fuel is burned and reacts with oxygen to produce water and carbon dioxide

Concentration Formula

= Mass of solute dissolved (grams)/Volume of Solvent Litres

Synthesis

reactants come together to create a single product:

Decomposition

where a single reactant breaks down into 2 (or more) products:

Are cataylsts used up in a reaction

catalysts are not used up in a reaction

How do catalysts help a reaction proceed more quickly

less energy required to break bonds, makes reaction quicker

Explain why the temperature of an endothermic reaction decreases despite having more energy than the reactants

energy from environment is absorbed in the reaction

this energy is then stored in the products making temperature decrease

Method to identifying oxygen or hydrogen gas

Put a glowing splint/match in the test tube, it reignites

How can temperature affect rate of reaction

higher temperature increases ROR due to more kinetic energy which makes particles collide more

How to Identify gases

Limewater test

bubble gas in limewater if it turns milk or cloudy it is insoluble

Which gas pops when tested with a lit match

hydrogen gas

TEMPERATURE Increase in reaction is a

exothermic reaction

TEMPERATURE Increase in reaction is a

endothermic reaction