JAMB UTME - Chemistry - 1982

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?

Antwoorddetails

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

Antwoorddetails

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

Antwoorddetails

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

Antwoorddetails

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?

Antwoorddetails

Which of the following represents ethyl ethanonate?

Antwoorddetails

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

Antwoorddetails

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?

Antwoorddetails

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)

Antwoorddetails

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

Antwoorddetails

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

Antwoorddetails

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)

Antwoorddetails

If the temperature of a gas is increased?

Antwoorddetails

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

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

Antwoorddetails

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.

Antwoorddetails

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?

Antwoorddetails

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

Antwoorddetails

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

Antwoorddetails

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)

Antwoorddetails

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)

Antwoorddetails

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

Antwoorddetails

Cotton is almost pure?

Antwoorddetails

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?

Antwoorddetails

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?

Antwoorddetails

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

Antwoorddetails

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

Antwoorddetails

Which of the following is NOT a redox reaction?

Antwoorddetails

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?

Antwoorddetails

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

Antwoorddetails

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?

Antwoorddetails

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

Antwoorddetails

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

Antwoorddetails

Which of the following statements is incorrect?

Antwoorddetails

Which of the following is a neutralization reaction? Addition of

Antwoorddetails

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

Antwoorddetails

An amphoteric oxide is an?

Antwoorddetails

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

Antwoorddetails

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?

Antwoorddetails

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

Antwoorddetails

Brass is an alloy containing copper and?

Antwoorddetails

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

Antwoorddetails

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

Antwoorddetails

An acid is said to be weak if?

Antwoorddetails

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

Antwoorddetails

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

Antwoorddetails

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

Antwoorddetails

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?

Antwoorddetails

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

Antwoorddetails

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?

Antwoorddetails