JAMB UTME - Chemistry - 1979
Pergunta 1 Relatório
Phosphorus burns in oxygen according to the equation P4 + 502 → P4O10. How many litres of oxygen will be required at S.T.P for complete oxidation of 12.4g of phosphorus? [P = 31,O = 16 and molar volume of a gas at S.T.P = 22.4 litres]
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Pergunta 2 Relatório
In the manufacture of iron in the blast furnace, iron (lll) oxide is mixed with coke and limestone, and different reactions occur in the process. Which of the following statements is true with respect to these reactions?
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Pergunta 3 Relatório
How many grams of HBr would exactly be required to react with 2 g of propyne? (C =12, H=1, Br = 80)
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Pergunta 5 Relatório
A gas occupies 30.0 dm3 at S.T.P. What volume would it occupy at 91oC and 380 mm Hg?
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Pergunta 6 Relatório
Which of the following statements is true? When the potassium atom forms its ion
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Pergunta 7 Relatório
When a piece of charcoal enclosed in a cylinder containing air is ignited
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Pergunta 8 Relatório
Indicate which of the following statements is not true as we move from left to right along the periodic Table:
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Pergunta 10 Relatório
If chlorine gas is bubbled into water and then this yellowish-green coloured solution is exposed to bright sunlight for a while
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Pergunta 11 Relatório
The oxidation state of manganese in potassium permanganate is
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Pergunta 12 Relatório
Which one of these compounds will NOT give an oxygen gas on heating?
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Pergunta 15 Relatório
Which of the following raw materials would be required from the smelting of iron ore in a blast furnace?
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Pergunta 16 Relatório
Methanoic acid mixes with water in all proportions and has about the same boiling point as water which of the following methods would you adopt to obtain pure water from a mixture of stand, water and methanoic acid?
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Pergunta 19 Relatório
Calcium hydroxide and ammonium chloride when heated together will give an important product. This compound may be obtained dry by
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Pergunta 21 Relatório
\(50cm^{3}\) of hydrogen are sparked with \(20cm^{3}\) of oxygen at \(100°C\) and \(1atm\) . The total volume of the residual gases in
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Pergunta 22 Relatório
0.1 Faraday of electricity was passed through a solution of copper (ll) sulphate. The maximum weight of copper deposited on the cathode would be [Cu = 64]
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Pergunta 24 Relatório
On heating anhydrous iron (ll) sulphate, in addition to producing iron (iii) oxide, which of the following is produced?
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Pergunta 25 Relatório
In which of the following reactions is sulphur dioxide acting as an oxidizing agent?
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Pergunta 26 Relatório
The reaction 3C(s) + 2Fe2O3(s) = 4Fe(s) + 3CO2(g): \(\Delta\)H =46.0 kJ is
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Pergunta 27 Relatório
An organic compound X has the following properties: I. It is not miscible with water. ll. lt has boiling point of 77oC lll. lt has a sweet odour lV. lt is insoluble in sodium hydrogen carbonate solution . V lt does not decolourize bromine water X is therefore
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Pergunta 28 Relatório
When ammonium, potassium and calcium carbonates are each separately heated
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Pergunta 29 Relatório
In the extraction of aluminum from purified bauxite by electrolysis, cryolite is used because
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Pergunta 30 Relatório
When carbondioxide is bubbled into limewater a white precipitate is formed. If the passage of the gas is continued, the precipitate disappears. The reason for this is
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Pergunta 31 Relatório
A piece of metal (M) is dissolved in nitric acid and the resulting solution is treated with a small quantity of sodium hydroxide to produce a white precipitate (B) which redissolves on the addition of excess alkali. The precipitate (B)when ignited in a crucible produces the oxide of the metal(m). The METAL M is
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Pergunta 32 Relatório
When excess ethanol is heated to 145 oC in the presence of concentrated sulphuric acid, the product is
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Pergunta 36 Relatório
In the electrolysis of dilute sulphuric acid using platinum electrodes, the products obtained at the anode and cathode are:
Anode Cathode
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Pergunta 37 Relatório
Which of the following substances are all made by the process of polymerization?
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Pergunta 39 Relatório
The reaction between hydrogen and iodine may be represented by the equation H2(g)+ I2(g) → 2HI(g), and is exothermic. Therefore
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Pergunta 40 Relatório
One of the following techniques can be used to show that chlorophyll pigment is a mixture of chemical compounds and not a single coloured compound
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Pergunta 41 Relatório
Weighed salts Y and Z were left exposed in the laboratory overnight. In the morning Y had gained weight, and Z had become liquid. What conclusion could be drawn about the nature of the two salts?
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Pergunta 42 Relatório
The empirical formula of an oxide of nitrogen containing 30.4 per cent of nitrogen is (N=14.0,O=16.0)
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Pergunta 43 Relatório
Which are the correct IUPAC names for H-CO2CH3 and CH = CH
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Pergunta 44 Relatório
12 g of solid protassium chlorate (KCIO) were added to 40 g of water and heated to dissolve all the solid. As the solution cools, crystals of potassium chlorate at 66 oC. The solubility of potassium chlorate at 66 oC is therefore
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Pergunta 45 Relatório
Which of the following statements applies during the electroysis of sodium hydroxide sodium hydroxide solution using platinum electrodes?
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Pergunta 47 Relatório
The solution of a sample in a tube will be identified as a chloride if it gives
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The solution of a sample in a tube will be identified as a chloride if it gives a white precipitate when acidified with dilute HNO3 and then AgNO3 solution is added. This is because the test is a confirmatory test for chloride ions, and the white precipitate formed is silver chloride (AgCl). Chloride ions react with silver nitrate (AgNO3) to form a white precipitate of AgCl, which is insoluble in water and dilute nitric acid.
Pergunta 48 Relatório
Consider the following exothermic reaction 2SO2(g) + O2(g) = 2SO3 (g) . If the temperature of the reaction is reduced from 800oC to 500oC, and no other change takes place, then
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Pergunta 49 Relatório
The reaction of zinc with copper (ll) ions in aqueous solution can be represented as follows: Cu 2+(aq) +Zn (s) → Cu(s) + Zn 2+(aq).Which of the following is the most complete description of this reaction?
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