chemistry paper 1 unfamiliar content Flashcards
explain why graphite is a good electrical conductor and slippery
-giant structure
-three covalent bonds per carbon atom
-so one electron per carbon atom (is delocalised)
* these delocalised electrons
* can move through the structure
* carrying (electrical) charge
* so graphite conducts electricity
layered structure
* of (interlocking) hexagonal rings
* with weak (intermolecular) forces between layers
why is graphite soft and slipper?(another point)
no (covalent) bonds between layers
* so the layers can slide over each other
* so graphite is soft and slippery
how do you work out the percentage atom economy?
desired product/reactant x 100
give two observations you could make when a small piece of potassium is added to water
-potassium floats/moves
-lilac flame
-fizzing
explain why reactivity of elements change going down group 1
-reactivity increases (going down
the group)
(because) the outer electron /
shell is further from the nucleus
(so) there is less attraction
between the nucleus and the
outer electron/shell
(so) the atom loses an electron
more easily
explain why sodium oxide has a high melting point
giant structure
(with) strong (electrostatic)
forces of attraction between
(oppositely charged) ions
(so) large amounts of energy
are needed to break the bonds
why should you warm up sulfuric acid when a student wants to make crystals of magnesium sulfate?
to speed up the reaction
why should you repeatedly add spatula of magnesium oxide to the beaker and stir it?
to make sure all the hydrochloric acid reacts
why should you filter the mixture?
to remove excess magnesium oxide
how should you evaporate the filtrate gently until crystals start to form?
use a boiling water bath or use an electric heater
in what state do metals conduct electricity?
solid, liquid,molten
