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Pergunta 1 Relatório
Crude copper can be purified by the electrolysis of CuSO4(aq) if?
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Pergunta 3 Relatório
What are the possible oxidation numbers of an element if its atomic number is 17?
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17 = 2, 8, 7
Pergunta 6 Relatório
A substance S is isomorphous with another substance R. When a tiny crystals of S is added into a supersaturated solution of R?
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Pergunta 7 Relatório
Which of the following statements is NOT correct?
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Increasing the pressure confines the gas molecules to a smaller space, thereby reducing the volume. Reducing the pressure the other way round increases the volume of a gas.
Pergunta 8 Relatório
Which of the following reactions takes place in the cathode compartment during the electrolysis of copper (II) chloride solution?
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Pergunta 9 Relatório
When H2S gas is passed into a solution of iron (III) chloride, the colour changes from yellow to green. This is because?
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Pergunta 10 Relatório
Which of the following acts as both a reducing and an oxidizing agent?
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Pergunta 11 Relatório
In the experiment above, ammonium chloride crystals deposit on the walls of the tube is as a result of
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Pergunta 13 Relatório
An increase in temperature causes an increase in the pressure of a gas because there is an increase in the?
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Pergunta 14 Relatório
Which of the following dilute solutions has the lowest pH value?
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Pergunta 15 Relatório
Which of the following in aqueous solution is neutral to litmus?
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Pergunta 16 Relatório
Which of the following physical properties decreases across the Periodic Table?
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Pergunta 17 Relatório
The ion that may be assumed to have negligible concentration in a sample of water that lathers readily with soap is?
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Pergunta 18 Relatório
In the experiment above, ammonium chloride crystals deposit on the walls of the tube is as a result of
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Pergunta 19 Relatório
Which of the following compounds has the highest boiling point?
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Pergunta 20 Relatório
An eruption pollution an environment with gas suspected to be H2S, a poisonous gas. A residue team should spray the environment with?
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Pergunta 21 Relatório
The energy changes accompanying the addition of an electron to a gaseous atom is called?
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Pergunta 22 Relatório
2.25g of a sample of an oxide of copper on reduction gave 2.0g of copper. 2.50g of another oxide of copper on reduction also gave 2.0g of copper. These results are in accordance with the law of?
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Pergunta 24 Relatório
The thermal decomposition of copper (ll)trioxonitrate (V) yields copper (ll) oxide, oxygen and?
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Pergunta 25 Relatório
A mixture of starch solution and potassium iodide was placed in a test tube. On adding dilute tetraoxosulphate (lV) acid and then K2Cr2O7 solutions, a blue-black colour was produced. In this reaction, the?
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Pergunta 27 Relatório
The formula of a compound formed in a reaction between a trivalent metal M and a tetravalent non-metal X is~?
Pergunta 28 Relatório
Use the graph above to answer this question. The mass of a substance, M, liberated at an electrode during electrolysis is proportional to the quantity of electricity, Q passing through the electrolyte. This is represented graphically by.
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Pergunta 29 Relatório
The acidic hydrogen in the compound is the hydrogen attached to carbon number
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Pergunta 30 Relatório
Which of the following will produce the greatest increase in the rate of the chemical reaction represented by the equation Na2S2O3(aq) + 2HCl(aq) → 2NaCI(aq) + H2O(I) + SO2(g) + S(g)?
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Pergunta 31 Relatório
The diagram above shows the reaction path of an exothermic reaction. The heat of reaction is represented by
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Pergunta 33 Relatório
Given the reactions (i) Fe(s) + X(NO3)2(aq) → Fe(NO3) + X(s) (ii) H2(g) + XO → X + H2O(s); X is likely to be?
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Pergunta 34 Relatório
Which property of a reversible reaction is affected by a catalyst?
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Pergunta 36 Relatório
Carbon (ll) oxide may be collected as shown above because it
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Pergunta 37 Relatório
The forces holding naphthalene crystals together can be overcome when naphthalene is heated to a temperature of 354K resulting in the crystal to melting. These forces are known as?
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Pergunta 39 Relatório
The molar ratio of oxygen to nitrogen in dissolved air is 2:1 whereas the ratio is 4:1 in atmospheric air because?
Pergunta 40 Relatório
Suitable reagents for the laboratory preparation nitrogen are?
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Pergunta 41 Relatório
Alkanoates are formed by the reaction of alkanoic acid with?
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Pergunta 42 Relatório
One mole of propane is mixed with five moles of oxygen. The mixture is ignited and the propane burns completely. What is the volume of the products at s.t.p?(G.M.V = 22.4 dm3 mol-1)
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C3H8 + 5O2 → 3CO2 + 4H2O
When the mixture is ignited CO2 is collected as product. From the equation 33 moles of CO2 is produced which equals 3 x 2.4 dm3 = 67.2 dm3 at S.T.P
Pergunta 43 Relatório
What process would coal undergo to give coal gas, coal tar, ammoniacal liquor and coke?
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Pergunta 44 Relatório
A metallic ion X2+ with an inert gas structure contains 18 electrons. How many protons are there in this ion?
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Pergunta 45 Relatório
What volume of a 0.1 M H3PO4 will be required to neutralize 45.0 cm3 of a 0.2 M NaOH?
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