Fuuuuckkkiiiiiiinnnn Flashcards
1.1 Give the number of electrons and neutrons in the aluminium atom
13
14
1.2 Aluminum is produced by the reduction of aluminum oxide (Al2O3). What is meant by the term reduction?
loss of oxygen
1.3 Explain why the positive carbon electrodes must be continually replaced.
at high temp oxygen reacts with carbon electrode so the positive electrode burns away to produce co2
1.4 Carbon electrode (made from graphite)…….
Molten mixture of aluminium oxide and cryolite………..
Metal wire…………..
delocalised electrons
ions
delocalised electrons
2.1 Suggest one limitation of using a ball and stick model for a water molecule.
its not to scale
2.2 Ice has a low melting point because theintermolecular forces are……………..
weak
2.3 What is the molecular formula of the molecule in Figure 3?
CH40
the 4 is meant to be small not big 4
2.4What is the number of bonds formed by each carbon atom in diamond?
4
2.5 Give twophysical properties of diamond
very hard
high melting point
2.6 Name two other substances with giant covalent structures.
graphite
silicon dioxide
3 Plan a method the students could use to test their hypothesis (6 mrks)
1.weigh test tube
add metal carbonate
weigh test tube and metal carbonate
2 .heat
allow it to cool
weigh test tube and metal oxide
repeat until no change in mass
4.1 Complete the equation for the reaction by writing the state symbols.
ZnO( ) + 2HCl( ) → ZnCl2( ) + H2O( )
ZnO(s) + 2HCl(aq) → ZnCl2(aq) + H2O(l)
4.2Give one way that the student could speed up the reaction between zinc oxide powder and hydrochloric acid
heat the mixture
4.3 How could the student know when all the hydrochloric acid has reacted?
the solid remains
4.4 How could the student obtain zinc chloride solution from the reaction mixture when all the hydrochloric acid has reacted?
filter it out
4.5 Describe how zinc chloride crystals are produced from zinc chloride solution.
heat it then leave it to cyrstalise
4.6 pH at start =
pH atend =
12
2
4.7 Complete the symbol equation for the preparation of sodium sulfate.
….NaOH + H2SO4 →……….+……….
2NaOH + H2SO4 →NA2SO4 + 2H20
4.8 What was the hydrogen ion concentration of the hydrochloric acid after water had been added?
0.10mol/dm^3
5.1 What is the dependent variable in this investigation?
temperature change
5.2 Suggest why the copper sulfate solution was left for four minutes before adding the magnesium.
to reach a constant temperature
5.5 Explain why the temperature of the mixture decreases after 7 minutes.
the reaction is finished so energy is lost to surroundings
5.6 Suggest the identity of metal Q. Give one reason for your answer.
Zinc
less reactive than magnesium
5.7A copper sulfate solution contained 0.100 moles of copper sulfate dissolved in 0.500 dm3 of water. Calculate the mass of copper sulfate in 30.0 cm3 of this solution. Relative formula mass (Mr): CuSO4 = 159.5
(moles= 30/500 x 0.1)=0.06
0.06 x 159.5= 0.957
6.1 What two conclusions can be made from the results? Tick two boxes
Atoms have a positively charged nucleus
Mass is concentrated in the nucleus in the centre of atoms
6.2The gold foil is 4.00 × 10^–7m thick and 2400 atoms thick. What is the diameter of one gold atom in metres? Give your answer to 3 significant figures.
4x10^-7
———– = 1.67x10^-10
2400
6.3 0.175 g of gold reacts with chlorine.The equation for the reaction is :2 Au + 3 Cl2→ 2 AuCl3 Calculate the mass of chlorine needed to react with 0.175 g of gold.Give your answer in mg Relative atomic masses (Ar): Cl = 35.5 Au = 197
0.175/197= 0.000888
0.000888 x 3/2=0.00133
0.00133x71=0.0946g
=94.6mg
7.1 Explain what happens to caesium atoms and to oxygen atoms when caesium reacts with oxygen to produce caesium oxide
caesium loses an electron
then oxygen atom gains 2 electrons
so two caesium atoms react with one oxygen atom to form CS+ and 02-
extra notes: caesium has positive charge and vice versa at the end of reaction
7.2 Explain why caesium is more reactive than sodium.You should answer in terms of electrons.
caesium has more energy levels
so the outer electron is further from the nucleus
so weaker attraction between the two
so the outer electron is more easily lost
Explain why the early periodic tables placed iodine (I) before tellurium (Te), but then Mendeleev placed tellurium before iodine.
early periodic tables were arranged in order of atomic weight
idodine has a lower atomic weight than tellurium
so mendeleev placed iodine with elements of the same properties
