1C June 2014 Flashcards
Why is the acid heated before reacting it with the metal?
Increase the rate of the reaction.
How could you tell when a substance is in excess?
It would stop dissolving.
Why do crystals form when a hot saturated solution is cooled?
Solubility decreases with temperature.
magnesium + hydrochloric acid
magnesium chloride + hydrogen
magnesium + steam
magnesium oxide + hydrogen
Solid lithium nitride conducts electricity, why would expect it not to?
Ions cannot move.
Explain why diamond has a high melting point.
Giant covalent structure, strong covalent bonds, lots of energy required to break bond.
Why do simple molecular structures have low melting points?
Intermolecular forces are weak.
Changes that occur in the formation of an addition polymer from its monomer?
Many monomers join up, double bonds become single bonds, increase in chain length.
Why is a burette used instead of a pipette for adding acid in titrations?
Different volumes can be measured.
