chem paper 3 Flashcards
What oxides do metals react to form?
Alkali oxides
What oxides to non-metals react to form?
Acidic Oxides
When would you use filtration?
To separate a solution from an INSOLUBLE SOLUTE
When would you use crystallisation?
To collect a SOLUBLE SOLUTE (note - it does not collect the solvent)
When would you use simple distillation?
To collect a solvent from a solution (of either solute or solvent)
When would you use fractional distillation?
To separate solvents of different boiling points
How did Mendeleev organise the periodic table?
By atomic weight and chemical properties - he also left gaps
When is it ionic / covalent / metallic or intermolecular bonds?
- metal and non-metal compounds : IONIC bonds
- non-metal compounds : COVALENT bonds
- metal compounds : METALLIC bonds
- particles : INTERMOLECULAR bonds
Why can polymers without cross-links stretch more than polymers with cross-links?
They have strong covalent bonds, but in those without cross-links, intermolecular forces are weak
How many covalent bonds do graphite and graphene have?
3 both - the difference is in the LAYER(S)
What sort of compounds can conduct electricity?
Metallic, and ionic IN A MOLTEN OR DISSOLVED STATE
What happens to inert copper electrodes in electrolysis
Decrease in mass of anode, because the copper takes part in the reaction
In an ionic compound, why can you conduct electricity in the aqueous state?
The ions are free to move. (NOT DE-LOCALISED ELECTRONS - THAT IS METALS)
What is a formulation?
A mixture with a specific and equal ratio of its components
What is a limiting reactant?
The reactant with the fewest moles - so used up first.
How can you tell a reaction is exothermic?
If more energy is RELEASED to make the bonds than TAKEN IN to break them
What oxides does metal react to form?
Alkali oxides
What oxides
ammonium?
NH4 +
hydroxide?
OH-
nitrate?
NO3 -
carbonate?
CO3 2-
sulfate?
SO4 2-
