EL 6, 7 Flashcards
what is the relative atomic mass of an element
- the mass of an atom relative to carbon-12
what is avogadros constant and what does it mean
- 6.02 x 10^23
- that is how many particles one mole of any substance will contain
how do you calculate the NoM
mass / RFM
what is the difference between the molecular formula and the empirical formula
- molecular formula tells you the actual amount of atoms in the molecule
- empirical formula is the simplified ratio of the molecular formula
what is water of crystallisation
- the molecules of water fitted within some crystals of ionic lattices in a regular manner
- this means that the crystals are hydrated
- when they are heated, the water is removed as steam and the solid is anhydrous
what are the factors that can reduce percentage yield
- loss of products from reactant vessels
- side reactions producing unwanted products
- impurities in the reactants
- changes in temperature and pressure
- if the reaction is in an equilibrium system
how do you calculate percentage yield
( experimental yield / theoretical yield ) x 100
what is a:
- cation
- anion
- positively charged ion
- negatively charged ion
describe ionic bonding
- occurs when a metal reacts with a non metal
- electrons are transferred from the metal atom to the non metal, giving them a stable electronic structure
- hold together by their opposite charges in an electrostatic bond
what is the formula are charge of the following ions:
- ammonium
- nitrate
- oxide
- lithium
- hydrogen carbonate
- sulphate
- NH4 +
- NO3 -
- O 2-
- Li +
- HCO3 -
- SO4 2-
what forms when you react the following:
- acid + alkali
- acid + base
- acid + carbonate
- acid + metal
- salt + water
- salt + water
- salt + water + carbo dioxide
- salt + hydrogen
- what are the ions that are EXCEPTIONS and are not soluble
- barium, calcium, lead and silver sulphates
- silver and lead halides
- all metal carbonates
- metal hydroxides (NOT group 1, or ammonium hydroxide)
what happens when you react sodium chloride and silver nitrate
- you form a white precipitate of silver chloride
- the only ions that get involved in the reaction is Ag+ and Cl-
what are spectator ions
Ions that don’t get involved in an ionic reaction
how do you identify copper and iron ions
- add sodium hydroxide to the sample
- COPPER, copper hydroxide precipitate, blue
- IRON (II), iron (II) hydroxide, dirty green
- IRON (III), iron (III) hydroxide, orange/brown