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Pregunta 1 Informe
In the extraction of iron, which of the following reactions does NOT take place in the blast furnace?
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Pregunta 2 Informe
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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Pregunta 3 Informe
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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Pregunta 4 Informe
The products of the reaction between dilute sulphuric acid and sodium thiosulphate crystals are?
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Pregunta 6 Informe
The brown coloration in nitric acid prepared in the laboratory can be removed by?
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Pregunta 7 Informe
Which of the following compounds and elements would sublime on exposure to the atmosphere?
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Pregunta 8 Informe
Sodium and potassium belong to the same group of the Periodic Table. This is because?
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Pregunta 10 Informe
Which of the following is NOT a true statement of the kinetic Theory of Gases?
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Pregunta 11 Informe
An element X has 127 neutrons and 82 electrons.
Its atomic number is?
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Pregunta 13 Informe
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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Pregunta 14 Informe
Which of the following is the electronic configuration of sodium?
(Atomic number of Na = 11)
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Pregunta 15 Informe
If an organic compound decolorizes bromine water then the compound is?
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Pregunta 17 Informe
Which of the following processes takes place during electrolysis?
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Pregunta 18 Informe
The scale formation in a kinetic used for boiling water is caused by the presence in water of?
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Pregunta 20 Informe
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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Pregunta 21 Informe
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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Pregunta 22 Informe
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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Pregunta 26 Informe
When hydrogen sulphide and sulphur dioxide are each passed in turn into a solution of potassium dichromate?
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Pregunta 28 Informe
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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Pregunta 29 Informe
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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Pregunta 30 Informe
the number of atoms in one mole of a substance is equal to?
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Pregunta 32 Informe
Which of the following statements is NOT true of electrovalent compounds?
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Pregunta 33 Informe
Which of the following statements about phosphorus is NOT correct?
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Pregunta 34 Informe
The general formula of an alkyl halide (which represent the halide) is?
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Pregunta 35 Informe
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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Pregunta 36 Informe
When a bottle of Coca-Cola is opened, bubbles of evolve. The gas is?
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Pregunta 37 Informe
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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Pregunta 38 Informe
In the reaction
C + 2HNO3 → CO2 + NO2 + NO + H2O nitric acid is acting as?
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Pregunta 40 Informe
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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Pregunta 42 Informe
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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Pregunta 43 Informe
Which of the following represents a precipitation reaction?
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Pregunta 44 Informe
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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Pregunta 45 Informe
In the reaction of oxygen with hydrogen to produce water, which of the following statements is true?
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Pregunta 46 Informe
What happens when the nitrates of potassium, calcium, zinc and copper are separately heated?
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Pregunta 47 Informe
When sodium nitrate dissolves in water, ∆H is positive. This means that?
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Pregunta 48 Informe
In the preparation of ammonia, which of the following is used as the drying agent?
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