JAMB UTME - Chemistry - 1978

Hypochlorous acid is used as a bleach because

When air which contains the gases Oxygen, nitrogen, carbondioxide, water vapour and the rare gases, is passed through alkaline pyrogallol and then over quicklime, the only gases left are;

Three solutions contain carbonate, sulphate and sulphide ions respectively. One test that will identify just ONE of them completely is by addition to each of them of

You are provided with five gas jars containing SO₂, CO₂, H₂, CO and NO respectively. Select a test from A to E which will identify ANY ONE of the gases completely

The reaction between an organic acid and an alcohol in the presence of an acid catalyst is known as;

A gas jar was inverted over burning yellow phosphorus floating over water in a beaker. After burning, the water level was found to rise in the gas jar. The water level rises because

When sodium chloride and metallic sodium are each dissolved in water

The normal boiling point of a liquid is defined as

An element X forms the following compounds with chlorine; XCl₄, XCl₃, XCl₂. This illustrates the

Which of the following reactions does not take place in the smelting of iron in a blast furnace?

When heat is absorbed during a chemical reaction, the reaction is said to be

Which of the following compounds will form a solution if exposed to air?

The oxidation state of chlorine in potassium chlorate is

Which of the following gases may not be dried with concentrated sulphuric acid?

The nucleus of an atom contains

Two gas cylinders contain ethylene (ethene) and acetylene respectively. One test which can be used to distinguish between them is by

Consider the following equation H₂O + 2Fe²⁺ + Cl₂ ↔ 2Fe³⁺ + 2Cl^- + H₂O. The only ion which behaves as an oxidising agent is

An experiment test of the Law of conservation of Mass is illustrated in the diagram. In practice, the flask is weighed before and after reaction between solutions X and Y. Which of the following pairs of solutions will be unsuitable for the experiments

A sample of hard water contains some calcium sulphate and calcium hydrogen carbonate. The total hardness may therefore be removed by

The pH of four solutions W, X, Y, Z are 4, 6, 8, 10 respectively, therefore

Consider the solubility curves of three salts X, Y and Z given in the diagram. If each solution of the salt contains 200 g, and is heated to 100^oC, which solution or solutions will deposit 100 g of the solute when suddenly cooled to 0^oC?

In the reaction between sodium hydroxide and sulphuric acid solutions, what volume of 0.5 molar sodium hydroxide would exactly neutralise 10cm3 of 1.25 molar sulphuric acid?

Which of the five atoms can be described by the following properties: Relative atomic mass is greater than 30 but less than 40, it has odd atomic number and forms a unipositive ion in solution?

Five compounds R,T,W,X and Y form the following compounds: a basic hydride R.H, an acidic hydride YH, atmospheric oxide W₂O₃, XO₂. which of the elements is an alkali

During the electrolysis of copper II sulphate between platinum electrodes, if litmus solution is added to the anode compartment,

Elements P, Q, R, S have 6, 11, 15, 17 electrons respectively, therefore,

If excess zinc is added to a bluish green solution of copper (II) sulphate, and the excess zinc filtered off after completion of reaction, a colourless solution is obtained because

By means of filtration, one component can be obtained pure from an aqueous mixture of sodium chloride and

A solid X when heated gives off a brown gas. If X is soluble in excess sodium hydroxide solution but insoluble in excess ammonium hydroxide solution, then X is

If 30cm³ of oxygen diffuses through a porous pot in 7 seconds, how long will it take 60cm³ of chlorine to diffuse through the same pot, if the vapour densities of oxygen and chlorine are 16 and 36 respectively?

The most common type of chemical reaction which alkanes undergo is

If hydrogen sulphide gas is passed into a solution of a pure iron chloride, a yellow deposit appears. If the deposit is filtered, a pale green solution is left behind. The pale green solution is

Which of the following metals cannot replace hydrogen from water or steam?

When large hydrocarbon molecules are heated at high temperature in the presence of a catalyst to give smaller molecules, the process is known as

In titration involving sodium hydroxide and dilute hydrochloric acid, where would you place the base?

Zinc Oxide is a

When each of the nitrates of Potassium, Magnesium and iron is heated,

The periodic classification of elements is an arrangement of the elements in order of their

Which of the following is not a member of the homologous series of the paraffins (alkanes)?

Which of the following changes is physical?

The IUPAC names of the compounds CH3COOH and CH2=CH2 are respectively;

Brass and bronze are both metallic alloys. Which of the following constituents is common to both alloys?

Which of the following substances would you see as an indicator in the titration of sodium carbonate solution against hydrochloric acid (complete neutralisation)?

An example of an alcohol is

When ammonia and hydrogen ion bond together to form ammonium ion, the bond formed is called

A small quantity of solid ammonium chloride (NH₄Cl) was heated gently in a test tube, the solid gradually disappears to produce two gases. Later, a white cloudy deposit was observed on the cooler part of the test tube. The ammonium chloride is said to have undergone

The size (diameter) of five elements are in the order R < T < W < X < Y, Y being the largest. If each atom has an electron situated on its circumference, and neglecting other factors, which of the atoms will lose its electron most reluctantly?

Consider the following exothermic reaction
2SO_2(g) + O_2(g) ↔ 2SO_3(g)
If the temperature of the reaction is reduced from 800°C to 500°C, an no other change takes place, then