GCSE EDEXCEL CHEMISTRY
CORRECT ANSWERS GRADED A+.
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Explain how the position of calcium tells us it is a metal? - correct-
answers-they are found on the left hand side of periodic table.
2Ca +02---->2CaO
Describe in terms of electron transfer what happens when calcium
reacts with oxygen. - correct-answers-calcium lsoes 2 electrons,
whereas oxygen gains 2 electrons.
describe the results in the table (electrolysis) and explain the results. -
correct-answers-mass of anode decreases after electrolysis. mass of
cathode increases after electrolysis. change in mass increases as
current increases.
copper atoms oxidised at anode and form cu2+
copper ions reduced at cathode and form cu.
beneath the copper anode, a sludge builds up. suggest an explanation
of the presence of the sludge. - correct-answers-impurities in copper
anode.
name another property that electrodes may have for them to be used
for electrolysis. - correct-answers-conduct electrcicity
write down half equation for reaction occuring at the graphite cathode.
- correct-answers-cu2+ + 2e- ->cu
use your knowledge of the structure and bonding of diamond and
graphite to explain the differences between properties shown in table.
- correct-answers-diamond
- each carbon in diamond forms 4 strong covalent bonds
- giant covalent structure
- high melting point and thus very hard to break requires alot of
energy to break the strong covalent bonds
CORRECT ANSWERS GRADED A+.
Save
Explain how the position of calcium tells us it is a metal? - correct-
answers-they are found on the left hand side of periodic table.
2Ca +02---->2CaO
Describe in terms of electron transfer what happens when calcium
reacts with oxygen. - correct-answers-calcium lsoes 2 electrons,
whereas oxygen gains 2 electrons.
describe the results in the table (electrolysis) and explain the results. -
correct-answers-mass of anode decreases after electrolysis. mass of
cathode increases after electrolysis. change in mass increases as
current increases.
copper atoms oxidised at anode and form cu2+
copper ions reduced at cathode and form cu.
beneath the copper anode, a sludge builds up. suggest an explanation
of the presence of the sludge. - correct-answers-impurities in copper
anode.
name another property that electrodes may have for them to be used
for electrolysis. - correct-answers-conduct electrcicity
write down half equation for reaction occuring at the graphite cathode.
- correct-answers-cu2+ + 2e- ->cu
use your knowledge of the structure and bonding of diamond and
graphite to explain the differences between properties shown in table.
- correct-answers-diamond
- each carbon in diamond forms 4 strong covalent bonds
- giant covalent structure
- high melting point and thus very hard to break requires alot of
energy to break the strong covalent bonds
