JAMB Chemistry 1994 Past Questions

A mixture of sand, ammonium chloride and sodium chloride is best separated by?

A pure solid usually melts?

At the same temperature and pressure, 50 cm³ of nitrogen gas contains the same number of molecules as?

8g CH₄ occupies 11.2 dm³ at s.t.p. What volume would 22 g of CH₃CH₃ occupy under the same condition?

(C = 12, H = 1)

To what temperature must a gas 273 K be heated in order to double both its volume and pressure?

For a gas, the relative molecular mass is equal to 2Y. What is Y?

The densities of two gases, X and Y, are 0.5 g dm^-3 and 2.0 dm^-3 respectively.
What is the rate of diffusion of X relative to Y?

The shape of ammonia molecule is?

An increase in temperature causes an increase in the pressure of a gas because?

The number of electrons in the valence shell of an element of atomic number 14 is?

Which of the following physical properties decreases down a group in the periodic table?

Element X, Y and Z belong to a groups I, V and VII respectively. Which of the following is TRUE about the bond types of XZ and YZ₃?

A solid that absorbs water from he atmosphere and forms an aqueous solution is?

A major effect of oil pollution in coastal waters is the?

Sodium chloride has no solubility product value because of its?

The solubility, in moles per dm³ of 20.2 g of potassium trioxonitrate (V) dissolve in 100 g of the resulting mixture is?

(K = 39, O = 16, N =14).

Which of the following atoms represents deuterium?

A few drops of concentrated PCI are added to about 10cm³ of a solution of pH 3.4. The pH of the resulting mixtures is?

Which of the following compounds is a base?

20 cm³ of a 2.0 M solution of ethanoic acid was added to excess of 0.05 M sodium hydroxide. The mass of the salt produced is?

(Na = 23, C = 12, O = 16, H = 1)

What volume of oxygen measured at s.t.p would be liberated on electrolysis by 9650 coulombs of electricity?



(Molar volume of gas = 22.4 dm³, F = 96,500 C mol^-)

Crude copper could be purified by the electrolysis of concentrated copper (II) chloride if the crude copper is?

H^- + H_2(I)O → H_2(g) + OH^-_(aq). From the equation above, it can be inferred that the?

An anhydride is an oxide of non-mental?

MnO_4(aq) + 8H + _(aq) + 5Fe²⁺ → Mn^2+(aq) + 4H₂O_(I). The oxidation number of manganese in the above reaction changed from?

Which of the following is TRUE of Le Chatelier's Principle for an exothermic reaction?

Which of the following are produced when ammonium trioxonitrate (V) crystals are cautiously heated in a hard glass round bottomed flask?

Which of these metals CANNOT replace hydrogen from alkaline solutions?

Clothes should be properly rinsed with water after bleaching because?

Which of these solutions will give a white precipitate with a solution of barium chloride acidified with hydrochloric acid?

SO₃ is NOT directly dissolved in water in the preparation of H₂SO₄ by the contact process because?

In an electrolytic set-up to protect iron from corrosion, the iron is?

Which of the following is NOT true of metals?

Which of the following is the correct order of decreasing activity of the metals Fe, Ca, Al and Na?

Which of the following compounds is NOT an isomers of 2,2 dimethylbutane?

When sodium is added to ethanol, the products are?

The general formula of alkanoates is?

One mole of a hydrocarbon contains 48 g of carbon. If it vapour density is 28, the hydrocarbon is?

Which of the following reagents will confirm the presence of unsaturation in a compound?

The diagram above represents an atom of

The set-up above would be useful for determining the amount of

The ∆H for the reaction represented by the energy profile above is

In the diagram above the activation energy is represented by

2HCL_(ag) + CaCO_3(ag) → CaCL_2(ag) + H₂O₍₁₎ + CO from the reaction above, which of the following curves represents the consumption of calcium trioxocarbonate (IV) as dilute HCL is added to it?

In the diagram above, R is a mixture of

The IUPAC name of the compound above is

Use the diagram above to answer this question. The reaction taking place in flask G is known as

MnO_4(aq) + 8H + 5Fe²⁺ \(\to\) Mn²⁺_(aq) + 5Fe³⁺_(aq) + H₂O. The oxidation number of maganese in the above reaction changed from

which of these metals CANNOT replace hydrogen from alkaline solutions?

Clothes should be properly rinsed with water after bleaching because