JAMB UTME - Chemistry - 1982

An amphoteric oxide is an?

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?

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

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.

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

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

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?

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

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?

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?

Which of the following is NOT a redox reaction?

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?

Which of the following represents ethyl ethanonate?

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?

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

If the temperature of a gas is increased?

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

An acid is said to be weak if?

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

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

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

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

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

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)

Water is poured over a white solid and a colourless neutral gas is evolved which burns with a sooty flame. The white solid is?

When a pressure cooker is half filled with water, and heated to boiling point, then the pressure inside the cooker will?

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

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?

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

Which of the following is a neutralization reaction? Addition of

Brass is an alloy containing copper and?

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?

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?

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

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

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)

60cm³ of hydrogen are sparked with 20cm³ of oxygen at 100°C and 1 atmosphere. The total volume of the residual gases is?

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)

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

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

An element X has two isotopes, ²⁰₁₀X and ²⁰₁₀X,
present in the ratio 1:3. The relative atomic mass of X would be?

What weight of sodium hydroxide is required to make 500 cm³ of 0.2 M solution?

(Na = 23, O = 16, H = 1)

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?

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

Cotton is almost pure?

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

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?

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)

Which of the following statements is incorrect?