JAMB Chemistry 1990 Past Questions

Which of the following is a physical change?

In a reaction: SnO + 2C → Sn + 2CO, the mass of coke containing 80% carbon required to reduce 0.302 kg of pure tin oxide is?
(Sn - 119, O - 16, C - 12).

Cr₂O₇ + 6Fe²⁺ + 14H⁺ → 2Cr³⁺ +6Fe³⁺ + 7H₂O. In the above , the oxidation number of chromium changed from?

In the reaction 1O^-₃ + 5l^- + 6H⁺ → 31₂ + 3H₂O, the oxidizing agent is?

Fe₂O_3(s) + 2Al_(s) → Al₂O₃ + 2Fe_(s) If the heats of formation of Al₂O₃ and Fe₂O₃ are - 1670 kj mol^-1 and - 822 kj mol^-1 respectively, the enthalpy change in kj for the reaction is ?

Iron galvanized with zinc is cathodically protected from corrosion. This is because?

Which of the following samples will react fastest with dilute trioxonitrate (V) acid?

In the reaction:
2Hl_(g) ↔ H_2(g) + l_2(g)' ΔH = 10 kj;

The concentration of iodine in the equilibrium mixture can be increased by?

Which of the following gases can be collected by the upward displacement of air?

The brown fumes given off when trioxonitrate (V) acid is heated consist of ?

Which of the following tests will completely identify anyone of surphur (VI) oxide, hydrogen, carbon (IV) oxide and nitrogen (II) oxide?

In the Haber process for the manufacture of ammonia, the catalyst commonly used is finely divided ?

A metallic oxide which reacts with both HCl and NaOH to give salt and water only can be classified as?

Which of the following metals will liberate hydrogen from steam or dilute acid?

Coal fire should not be used in poorly ventilated rooms because ?

The major component of the slag from the production of iron is?

Sodium hydrogen should be stored in properly closed containers because it?

To make coloured glasses, small quantities of oxides of metals which form coloured silicates are often added to the reaction mixture consisting of Na₂CO₃ and SiO₂. Such a metals is a?.

Which of the following compounds gives a yellow residue when heated and also reacts with aqueous sodium hydroxide to give a white gelatinous precipitate soluble in excess sodium hydroxide solution?

A cycloalkane with the molecular formula C₅H₁₀ has ?

The label on a reagent bottle containing a clear organic liquid dropped off.The liquid was neutral to litmus and gave a colourless gas with metallic sodium. The liquid must be an?

Alkaonic acids have low volatility compared with alkanols because they?

The octane number of a fuel whose performance is the same as that of a mixture of 55 g of 2,2,4- trimethly pentane and 45 g of n-heptane is ?

Which of the following is formed when maltose reacts with concentrated tetraoxosulphate (VI) acid ?

If a gas occupies a container of volume 146 cm³ at 18°C and 0.97`atm, its volume 146cm³ at s.t.p is?

The volume occupies by 1.58g of a gas at s.t.p is 500cm³. What is the relative molecular mass of the gas?

(G.M.V at s.t.p = 22.40dm³)

Equal volumes of CO,SO₂, and H₂S were released into a room at the same point and time. Which of the following gives the order of diffusion of the gases to the opposite corner of the room?
(S = 32, C = 12, O = 16, N = 14, H = 1)

A basic postulate of the kinetic theory of gases is that the molecules of a gas move in straight lines between collisions. This implies that?

.....................P....Q.....R......S
Proton..............13....16....17.....19
Electron............13....16....17.....19
Neutron.............14....16....35.....20

Which of the four atoms P,q,R and in S in the above data can be described by the following properties relative atomic mass is greater than 30 but less than 40; it has an odd atomic number and forms a unipositive ion in solution?

Which of the following terms indicates the number of bonds that can be formed by an atom?

X_(g) → X_(g). The type of energy involved in the above transformation is?

Chlorine, consisting of two isotopes of mass numbers 35 and 37, has an atomic mass of 35.5.
The relative abundance of the isotope of mass number 37 is?

10.0 dm³ of air containing H₂S as an impurity was passed through a solution of Pb(NO₃)₂ until all the H₂S had reacted. The precipitate of PbS was found to weigh 5.02 g. According to the equation:

Pb(NO₃)₂ + H₂S → PbS + 2HNO₃ the percentage by volume of hydrogen sulphide in the air is?



(Pb = 207, S = 32, GMV at s.t.p = 22.4dm³)

A blue solid, T, which weighed 5.0g was placed on a table. After 8 hours, the resulting pink solid was found to weigh 5.5g. It can be inferred that substance T?

The solubility in moles per dm³ of 20g of CuSO₄ dissolve in 100 of water at 180°C is?

(Cu = 63.5, S = 32, O = 16)

Smoke consist of?

Na₂C₂O₄ + CaCl₂ → CaC₂O₄ + 2NaCl. Given a solution of 1.9g of sodium oxalate in 50g of water at room temperature, calculate the minimum volume of 0.1 M calcium oxalate using the above equation?

2.0g of a monobasic acid was made up to 250 cm³ with distilled water. 25.00 cm³ of this solution required 20.00cm³ of 0.1 M NaOH solution for complete neutralization. The molar mass of the acid is?

What is the concentration of H⁺ ions in moles per dm³ of a sodium of pH 4.398?

What volume of 11.0 M hydrochloric acid must be dilute to obtain 1 dm³ of 0.05 M acid?

If 10.8 g of silver is deposited in a silver coulometer volume of oxygen liberated is?

0.1 faraday of electricity deposited 2.95 g of nickel during electrolysis of an aqueous solution.
Calculate the number of moles of nickel that will be deposited by 0.4 faraday?

(Ni = 58.7)

Changes in the physical in the scheme above.The letter X,Y and Z respectively represent

Use the graph above to answer this question. The structure of cis-2-butene is

What is the IUPAC name for the hydrocarbon

Use the above graph above to answer this question . CH₃-C = CH \(\frac{Na}{liq NH_3}\)> P, Compound P, in the above reaction, is

The above reaction is an example of

Select the right answer from the structure above.Which of the following compounds represents the polymerization product of ethyne?

The Avogadro number of 24g of magnesium is the same as that of