General Chem Flashcards
Propanone is a liquid with a low boiling point. Why?
The IMF are weak
Give some uses of fullerenes
drug delivery,catalyst,antioxidants,lubricants
Explain why Graphite is
-a good electrical conductor
-soft and slippery
answer in terms of structure and bonding
-giant covalent
-3 bonds for each atom so 1 free electron per carbon
-these delocalised electrons can move and carry charge
-layered hexagonal structure
-layers can slide due to weak imf
what is an isotope?
atoms with the same number of protons but dif. numbers of neutrons (isotopes aren’t variants!)
Gallium was discovered 6 yrs after Mendeleev published the periodic table. two reasons why its discovery helped mendeleev’s table to become accepted
It fit a gap he’d left
Its properties matched his predictions
examples of observations you could make when potassium is added to water
effevescence
K melts and becomes smaller
lilac flame
explain why reactivity goes down group 1
outer electron shell is further from nucleus further down the group as atoms get larger
less attraction between the nucleus and the outer electron
atom loses electrons more easily
so reactivity goes down
why is is called a reduction reaction?
it’s gaining electrons so losing charge
why does sodium oxide have a high melting point apart from the strong ionic bonds
Mention the giant ionic lattice structure. Giant things have high MPs
How should filtrate be evaporated in recrystallisation?
Use a water bath, electric heater, leave on windowsill. basically do it gently
why are alloys harder than pure metals
different sized atoms
other atoms disrupt the layers
layers can’t slide as easily
a solution is made by dissolving 1g of hydrogen chloride in 1dm^3 of water
a dilute solution of a strong acid
how to improve the accuracy of a titration
repeat for concordant results, add solution dropwise, use white tile to make colour change more obvious, swill the conical flask
name a gas not normally present in the atmosphere
hydrogen
describe the co2 test
bubble gas through limewater
will turn milky/cloudy in presence of co2
