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Pergunta 1 Relatório
0.16g of methane when burnt raises the temperature of 100g of water by 40°C. What is the of combustion of methane when if the heat capacity of water is 4.2 Jg-1°C-1?
(CH4 = 16)
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Pergunta 4 Relatório
Which of the following is a neutralization reaction? Addition of
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Pergunta 6 Relatório
Which of the following CANNOT be obtained by fractional distillation of petroleum?
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Pergunta 7 Relatório
The solubility curve of a solid X (molecular mass = 160) is as show above. 1,000 cm3 of a saturated solution of X at 80°C is cooled to 40°C . The weight of X crystalized out would be
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Pergunta 8 Relatório
Magnesium ribbon was added to each of the following aqueous solution in turn: H2SO4, AgNO3, HNO3, HCl, NH3, HCl, NH3. In which case does the magnesium become covered with a dark precipitate?
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Pergunta 9 Relatório
Which of the following combinations of conditions may increase the rate of a chemical reaction?
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Pergunta 10 Relatório
When air is passed through alkaline pyrogallol and then over quicklime, the only gases left are?
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Pergunta 11 Relatório
9.8g of solid potassium chlorate (KCIO3) were added to 40 cm3 of water and heated to dissolve all the solid. As he solution cooled, crystals of potassium chlorate started forming at 60°C. The solubility of potassium chlorate at 66°C is therefore?
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Pergunta 12 Relatório
The product formed at the the cathode during the electrolysis of sodium chloride solution with carbon electrodes is?
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Pergunta 13 Relatório
60cm3 of hydrogen are sparked with 20cm3 of oxygen at 100°C and 1 atmosphere. The total volume of the residual gases is?
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Pergunta 14 Relatório
What weight of sodium hydroxide is required to make 500 cm3 of 0.2 M solution?
(Na = 23, O = 16, H = 1)
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Pergunta 15 Relatório
When a little brine was added to a metal nitrate a white precipitate was formed which first turned violet and then black on exposure to ai. The metal nitrate is therefore?
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Pergunta 16 Relatório
Which of the following types of reactions takes place between C2H4 and the halogens?
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Pergunta 18 Relatório
Water is poured over a white solid and a colourless neutral gas is evolved which burns with a sooty flame. The white solid is?
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Pergunta 19 Relatório
The nitrogen gas obtained by burning an excess of phosphorus in air has a density higher than the nitrogen from nitrogen compounds because the nitrogen from air is contaminated with?
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Pergunta 20 Relatório
Which of the following statements is correct during the electrolysis of a caustic soda solution using platinum electrodes?
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Pergunta 21 Relatório
The pressure on 100 cm3 of oxygen gas at 35°C is 750mm of Hg.What would be the volume of the gas if the pressure is increased to 1000mm of Hg without changing the temperature?
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Pergunta 23 Relatório
1.00 g of the oxide of metal X (atomic mass = 64) gave 0.80 g of the metal when reduced with hydrogen.
The formula of the oxide is?
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Pergunta 24 Relatório
0.07g of a hydride of carbon occupies 56.0cm3 at S.T.P. when vaporized and contains 14.29% by mass of hydrocarbon is(C = 12, H = 1)
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Pergunta 25 Relatório
In the chemical reaction A + B \(\to\) C + D, more of D is formed?
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Pergunta 27 Relatório
How many grams of methylacetylene (propyne) CH3 — C Ξ CH will completely discharge the colour of 8g of bromine?
(Br = 80, C = 12, H = 1)
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Pergunta 28 Relatório
Which of the following bonds exist in crystalline ammonium chloride (NH4Cl)?
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Pergunta 30 Relatório
If the rate of diffusion of oxygen gas is taken as 1, what will be rated of diffusion of methane whose relative molar mass is 16?
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Pergunta 31 Relatório
If atom X with six electrons in its outermost shell combines with atom Y with one electron in its outermost shell to form an ionic compound, then?
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Pergunta 32 Relatório
Which of the following equations represents an oxidizing action of sulphur dioxide?
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Pergunta 33 Relatório
100 cm3 of oxygen is made to react with 50 cm 3 of hydrogen, and the whole reaction mixture was then passed through anhydrous calcium chloride. What is the volume of gas left?
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Pergunta 34 Relatório
A mixture contains 20cm3 of hydrogen, 35cm3 of oxygen, 15cm3 of carbon monoxide and 10cm3 of nitrogen at S.T.P. Which of the following gives the mole fraction of hydrogen in this mixture?
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Pergunta 35 Relatório
An element X has two isotopes, 2010X and 2010X,
present in the ratio 1:3. The relative atomic mass of X would be?
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Pergunta 36 Relatório
In the reaction N2(g) + O(g)
↔ 2NO(g) produced i an increase in the total pressure will?
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Pergunta 37 Relatório
The production of ammonia by the haber process may be represented by the equilibrium equation N2(g) + 3H2(g) ↔ 2NH3 ∆H = -22KJ. Therefore the production of ammonia will be favoured by?
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Pergunta 38 Relatório
Sodium carbonate crystals on exposure to a dry atmosphere change to a white powder. This phenomenon is known as?
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Pergunta 39 Relatório
1.00g of mixture of calcium carbonate and calcium oxide liberated 0.33g of carbon dioxide on strong heating. The percentage of calcium oxide in the mixture is? (Ca = 40, C = 12, O = 16)
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Pergunta 40 Relatório
When a solution of silver (l) nitrate is saturated with hydrogen sulphide, a black precipitate forms which is?
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Pergunta 42 Relatório
In the preparation of carbon monoxide by heating ethanedioic acid with concentrated sulphuric acid, the concentrated sulphuric acid act as?
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Pergunta 43 Relatório
In the reaction NH3 + H+ → NH4+, the bond formed results from?
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Pergunta 44 Relatório
When a pressure cooker is half filled with water, and heated to boiling point, then the pressure inside the cooker will?
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Pergunta 46 Relatório
Which of the following processes NOT lead to a chemical change?
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Pergunta 47 Relatório
A current of 10.0A was passed for 1 hour through a solution of copper (ll) sulphate between the copper electrodes. Which of the following observation would be correct?
(1 Faraday = 96,500 coulobms) (i) 0.186 mole of copper is dissolved from the anode. (ii) 0.372 mole of copper is deposited on the cathode. (iii) the original Cu2+ ion concentration of the solution remains unchanged. (iv) the original Cu2+ ion concentration of the solution decreases.
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Pergunta 48 Relatório
When copper powder is heated with concentrated sulphuric acid, the gas produced is?
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Pergunta 49 Relatório
The number of grammes of potassium hydroxide in 250cm3 of one molar solution is?
(K = 39, O = 16, H = 1)
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