JAMB Chemistry 1983 Past Questions

X is a crystalline salt of sodium solution of X in water turns litmus red and produces a gas which turns lime water milky when added to sodium carbonate. With barium chloride solution, X gives hydrochloric acid. X is

The alkanol obtained from the production of soap is

The flame used by welders in cutting metals is

Consecutive members of an alkane homologous serires differ by

If an element has the electronic configuration 1s ² 2s² 2p³ 3s² 3p⁴, it is

Some copper (ll) sulphate pentahydrate (CuSO₄ 5H₂O), was heated at 120 ^oC with the following results. Wt of crucible = 10.00 g; Wt of crucible + CuSO₄ 5H₂O =14.98g; Wt of crucible + residue = 13.54 g. How many molecules of water of crystalization were lost?

[H = 1, Cu = 63.5, O = 16, S = 32]

The three-dimensional shape of methane is

An unknown organic compound X has a relative molecular mass of 180. It is a colourless crystaline solid, readily soluble in water. X contains the elements C, H and O in the atomic ratio 1: 2:1. The compound has a sweet teste and melts on heating. In the presence of yeast and in the absence of air, X is converted to compound Y and a colourless gas. Compound Y reacts with sodium metal to produce a gas Z which gives a 'pop' sound with a glowing splint. Y also reacts with ethanoic acid to give a sweet smelling compound W.

Compound W is

An unknown organic compound X has a relative molecular mass of 180. It is a colourless crystaline solid, readily soluble in water. X contains the elements C, H and O in the atomic ratio 1: 2:1. The compound has a sweet teste and melts on heating. In the presence of yeast and in the absence of air, X is converted to compound Y and a colourless gas. Compound Y reacts with sodium metal to produce a gas Z which gives a 'pop' sound with a glowing splint. Y also reacts with ethanoic acid to give a sweet smelling compound W.

The molecular formula of X is

An unknown organic compound X has a relative molecular mass of 180. It is a colourless crystaline solid, readily soluble in water. X contains the elements C, H and O in the atomic ratio 1: 2:1. The compound has a sweet teste and melts on heating. In the presence of yeast and in the absence of air, X is converted to compound Y and a colourless gas. Compound Y reacts with sodium metal to produce a gas Z which gives a 'pop' sound with a glowing splint. Y also reacts with ethanoic acid to give a sweet smelling compound W.

Reaction of X with yeast forms the basis of the

A mixture of common salt, ammonium chloride and barium sulphate can best be separated by

Which of the following relationships between the pressure P, the volume V and the temperature T, represents an ideal gas behaviour?

The colour imparted to a flame by calcuium ion is

In the reaction M + N P;∆H = + QKJ. Which of the following would increase the concentration of the product?

In which of the following processes is iron being oxidized?

1 Fe + H₂SO₄ → FeSO₄ +H₂

2 FeSO₄ + H₂S → FeS + H₂SO₄

3 2FeCI₂ + Cl₂ → 2FeCl₃

4 2FeCl₃ + SnCl₂ + → 2FeCl₂ + SnCl₄

In the reaction Fe + Cu²⁺ \(\to\) Fe²⁺ + Cu,iron displaces copper ions to from copper. This is due to the fact that

C₂H₅ - C = CH₂
CH₃

The correct name of the compound with the above structural formula is

How many isomeric forms are there for the molecular formula C₃H₆Br₂?

A piece of burning sulphur will continue to burn in a gas jar of oxygen to give misty fumes which readily dissolved in water. The resulting liquid is

Sodium sulphate decahydrate (Na₂SO₄.10 H₂O) on exposure to air loses all its water of crystallization.
The process of loss is known as

Which of the following happens during the electrolysis of molten sodium chloride?

Crude petroleum pollutant usually seen on some Nigerian creeks and waterways can be dispersed or removed by

An element is electronegative if

Solutions X, Y, and Z have PH values 3.0. 5. 0 and 9. 0 respectively. Which of the following statements is correct?

In the reactions

(I) H₂ (g) + 1/2O₂(g) → H₂O(l); ∆H = -286 KJ

(II) C(s) + O₂g) → CO₂ (g); ∆H = -406 KJ the equations imply that

Which of these metals, Mg, Fe, Pb and Cu will dissolve in dilute HCI?

Stainless steel is an alloy of

Which volume of 0.5 M H ₂SO₄ will exactly neutralize 20 cm ³ of 0.1 M NaOH solution?

Which of the following pair of gases will NOT react further with oxygen at a temperature between 30^oC AND 400^oC

Some metals are extracted from their ores after some preliminary treatments by electrolysis (L), some of both processes (TL). Which set-up in the following for the extraction of ion, copper and aluminium is correct?

In the preparation of some pure crystals of Cu (NO₃)₂ starting with CuO, a student gave the following statements as steps he employed. Which of these shows a flaw in his report ?

Which of the following separation processes is most likely to yield high quality ethanol (>95%) from palm wine?

Increasing the pressure of a gas

2.5 g of a hydrate barium salt gave on heating, 2.13 g of the anhydrous salt. Given that the relative molecular mass of the of the anhydrous salt is 208, the number of molecules of water of crystallization of the barium salt is

3. 06 g of a sample of potassium trioxochlorate (V) (KCIO) was required to make a saturated solution with 10cm³ of water at 25^oC. The solubility of the salt at 25^oC is [K =39, Cl = 35.5, O = 16]

The cracking process is very important in the petroleum industry because it.

A gas that can behave as a reducing agent towards chlorine and as an oxidizing agent toward hydrogen sulphide is

Which of the following solutions will give a white precipitate with barium chloride solution and a green flame test?

The mass of an atom is determined by

Which of the following is a neutralization reaction?

A jet plane carrying 3,000 kg of ethane burns off all the gas forming water and carbondioxide. if all the carbondioxide is expelled and all the water formed is condensed and kept on board the plane, then the gain in weight is

Liquid X, reacts with sodium trioxocarbonate (IV) (Na₂CO₃) to give a gas which turns calcium chloride solution milky X is

Which of the following statements is FALSE?

When sodium dioxonitrate (lll) (NaNO₂) dissolves in water, ∆H is positive. The process of dissolution is

The equilibrium reaction between copper (l) chloride and chlorine at 25^oC and 1 atmosphere is represented by the equation:
2CuCl +Cl₂ ⇌ 2 CuCl₂ ∆H = - 166 KJ. Which of the following statements is TRUE for the reaction, pressure remaining constant?

zn + 2HCl → ZnCl₂ + H₂

The rate of the above reaction will be greatly increased if

Zn + H₂ SO₄ → ZnSO₄ + H₂

in the above reaction how much zinc will be left of 1.0 M of H₂SO?
[Zn =65, s = 32, O = 16, H = 1]

30 cm³ of 0.1 M Al (NO₃)₃ SOLUTION IS RECTED WITH 100cm³ of 0.15M of NaOH solution. Which reactant is in excess, and by now much ?

In the above experiment, the litmus paper will initially

In the experiment above, a current was passed for 10 minutes and 0.63g of copper was found to be deposited on the cathode of CuSO₄ cells. The weight of silver deposited on the cathode og AgNO³ cell during the same period would be? [Cu = 63, Ag = 108]