Chemistry all content from part 2

Acid

produces H pos when dissolved in water. pH below 7

Base

produces a reaction to an acid to neutralise it. ph above 7

Types of acid reactions

Acid + metal → salt + hydrogen
Acid + base → salt + water
Acid + carbonate → salt + water + carbon dioxide

Ionic bonding

metal + non metal
Electrons are transferred from atom to another creating pos and neg ions that attract to each other

Covalent bonding

Non- metal + non-metal
Atoms share electrons so both can become more stable

Metallic bonding

metal + metal
metal atoms outer electrons become delocalized (can move freely through the metal) so the positive metal ions are attracted to these moving electrons.

Participate reactions

two aq solutions mix to produce an insoluble solution.
*use solubility rules

Displacement reaction

one element replaces another element or compound.
*use reactivity series

Combustion reaction

substance reacts with oxygen and elases energy usually in the form of heat or light

Corrosion reaction

Metal reacts with a substance in its environment, causing it to gradually break down

Exothermic reaction

Releases energy into surroundings, and they get warmer.
Old bonds are broken which absorbs energy but new bond also form relasing energy which is greater than the old bonds.

Endothermic reactions

Absorbs energy, surroundings get cooler. New bonds formed are weaker than the old ones so breaking bonds abosrbs nenrgy old greater than the new.

Synthesis reaction:

Two or more substances combine to produce one product A+B→AB

Decomposition reaction

One compound breaks down into two or more products
AB→ A + B

Neutralisation reactions

Acid reacts with a base to produce a salt + water

Mole calculations

counts particles
n=m/M
n is no of mols
m is mass in g and
M is molar mass (atomic mass)