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Pergunta 2 Relatório
In the extraction of iron, which of the following reactions does NOT take place in the blast furnace?
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Pergunta 4 Relatório
Which of the following represents a precipitation reaction?
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Pergunta 5 Relatório
The electronic configuration of elements X and Y are X = 2, 8, 6; Y = 2, 8, 7. The bond in the compound formed by X and Y is expected to be?
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Pergunta 7 Relatório
When hydrogen sulphide and sulphur dioxide are each passed in turn into a solution of potassium dichromate?
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Pergunta 8 Relatório
What happens when the nitrates of potassium, calcium, zinc and copper are separately heated?
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Pergunta 9 Relatório
Which of the following statements about phosphorus is NOT correct?
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Pergunta 10 Relatório
In the reaction of oxygen with hydrogen to produce water, which of the following statements is true?
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Pergunta 11 Relatório
5cm3 of a saturated solution of sodium chloride at 30°C gave, on careful evaporation, 1.95g of solid salt. The solubility of sodium chloride at 30°C?
(Na = 23, Cl = 35.5)
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Pergunta 13 Relatório
Sodium and potassium belong to the same group of the Periodic Table. This is because?
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Pergunta 14 Relatório
An element X has 127 neutrons and 82 electrons.
Its atomic number is?
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Pergunta 15 Relatório
Which of the following is NOT a true statement of the kinetic Theory of Gases?
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Pergunta 16 Relatório
The following compounds are given with their corresponding boiling points.
Compound Boiling Point
i.................................14°C
ii................................24°C
iii................................0°C
iv................................120°C
V.................................-2°C
From the above information, indicate which of the following is correct?
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Pergunta 17 Relatório
The general formula of an alkyl halide (which represent the halide) is?
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Pergunta 18 Relatório
Which one of the following metals is not normally extracted by chemical reduction because of its position in the electrochemical series?
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Pergunta 20 Relatório
If concentrated sulphric acid is added to sugar and warmed gently, the sugar changes from white to brown and finally to a black mas of carbon. In this reaction, concentrated sulphuric acid is acting as ?
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Pergunta 23 Relatório
Which of the following compounds and elements would sublime on exposure to the atmosphere?
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Pergunta 24 Relatório
What mass of sodium carbonate solution is in 500 cm3 of 0.1 molar sodium carbonate solution?
(Na = 23, C = 12, O = 16)
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Pergunta 26 Relatório
When a bottle of Coca-Cola is opened, bubbles of evolve. The gas is?
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Pergunta 27 Relatório
Which of the following statements is NOT true of electrovalent compounds?
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Pergunta 28 Relatório
Pure sulphuric acid is a liquid of 1:84 density. What volume of it would be required to prepare 250 cm3 of 2.0 M solution?
(H = 1, S = 32, O = 16)
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Pergunta 29 Relatório
If an organic compound decolorizes bromine water then the compound is?
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Pergunta 30 Relatório
Na2CO3 + 2HCI → 2NaCI + H2O + CO2. Using the above equation, what volume of carbondioxide, measured at s.t.p is liberated when 53g of sodium carbonate is dissolved in hydrochloric acid?
(1 mole of gas occupies 22.4 dm3 at s.t.p)
(Na = 23, C = 12, O = 16)
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Pergunta 31 Relatório
4g each of aluminium foil and aluminium powder were introduced respectively into flasks P and Q.
Flask P was treated with warm bench sodium hydroxide and all the aluminium dissolved in one hour. Flask Q was treated with cold sodium hydroxide and all the aluminium dissolved in 10 minutes. What was responsible for Q reacting faster than P?
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Pergunta 32 Relatório
If 48,000 coulombs of electricity are required to discharge 0.5 mole of sodium from a molten sodium chloride mass, then the number of coulombs required to discharge 2 moles of lead from molten lead (ll) chloride is?
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Pergunta 33 Relatório
When sodium nitrate dissolves in water, ∆H is positive. This means that?
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Pergunta 34 Relatório
When glowing splint is inserted into the mouth of a jar containing a gas, the splint is extinguished. The gas gives a white precipitate when passing into barium hydroxide. The gas is?
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Pergunta 35 Relatório
Which of the following processes takes place during electrolysis?
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Pergunta 36 Relatório
the number of atoms in one mole of a substance is equal to?
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Pergunta 38 Relatório
In the reaction
C + 2HNO3 → CO2 + NO2 + NO + H2O nitric acid is acting as?
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Pergunta 39 Relatório
The products of the reaction between dilute sulphuric acid and sodium thiosulphate crystals are?
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Pergunta 40 Relatório
In the preparation of ammonia, which of the following is used as the drying agent?
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Pergunta 42 Relatório
Which of the following is the electronic configuration of sodium?
(Atomic number of Na = 11)
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Pergunta 43 Relatório
The brown coloration in nitric acid prepared in the laboratory can be removed by?
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Pergunta 46 Relatório
If one mole of aluminium contains 6 x 1023 atoms of aluminium, how many atoms are contained in 0.9g of aluminium?
(Al = 27)
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Pergunta 48 Relatório
28.8 cm3 of nitrogen at 15°C is cooled to O°C at constant pressure, the new volume of nitrogen is?
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Pergunta 49 Relatório
The scale formation in a kinetic used for boiling water is caused by the presence in water of?
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