JAMB UTME - Chemistry - 1982

Sodium carbonate crystals on exposure to a dry atmosphere change to a white powder. This phenomenon is known as?

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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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An amphoteric oxide is an?

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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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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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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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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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Which of the following combinations of conditions may increase the rate of a chemical reaction?

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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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An acid is said to be weak if?

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In the chemical reaction A + B \(\to\) C + D, more of D is formed?

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The i.u.p.A.C name for the compound

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The product formed at the the cathode during the electrolysis of sodium chloride solution with carbon electrodes is?

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Which of the following equations represents an oxidizing action of sulphur dioxide?

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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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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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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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Cotton is almost pure?

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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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Which of the following processes NOT lead to a chemical change?

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When copper powder is heated with concentrated sulphuric acid, the gas produced is?

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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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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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In the preparation of carbon monoxide by heating ethanedioic acid with concentrated sulphuric acid, the concentrated sulphuric acid act as?

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When a solution of silver (l) nitrate is saturated with hydrogen sulphide, a black precipitate forms which is?

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Which of the following CANNOT be obtained by fractional distillation of petroleum?

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Which of the following statements is incorrect?

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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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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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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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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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Which of the following is a neutralization reaction? Addition of

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In the reaction NH₃ + H⁺ → NH₄⁺, the bond formed results from?

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Which of the following represents ethyl ethanonate?

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Which of the following statements is correct during the electrolysis of a caustic soda solution using platinum electrodes?

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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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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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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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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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Which of the following is NOT a redox reaction?

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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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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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The number of grammes of potassium hydroxide in 250cm³ of one molar solution is?
(K = 39, O = 16, H = 1)

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Which of the following bonds exist in crystalline ammonium chloride (NH₄Cl)?

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Brass is an alloy containing copper and?

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In the reaction N₂(g) + O(g)
↔ 2NO(g) produced i an increase in the total pressure will?

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When air is passed through alkaline pyrogallol and then over quicklime, the only gases left are?

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If the temperature of a gas is increased?

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Which of the following types of reactions takes place between C₂H₄ and the halogens?

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