JAMB CHEMISTRY PRACTISE QUESTIONS - II

6AgNO₃(aq) + PH₃(g) + 3H₂O(l) → 6Ag(s) + H₃PO₃(g) + 6HNO₃(aq) In the above reaction, the reducing agent is

• HNO₃(aq)
• PH₃(g)
• AgNO₃(aq)
• H₂O(l)

The IUPAC nomenclature of the compound LiAlH₄ is

• lithiumtetrahydridoaluminate (III)
• aluminium tetrahydrido lithium
• lithium aluminium hydride
• tetrahydrido lithium aluminate (III)

Iron can be protected from corrosion by coating the surface with

• gold
• silver
• copper
• zinc

What quantity of aluminium is deposited when a current of 10A is passed through a solution of an aluminium salt for 1930s? [Al = 27, F = 96500Cmol]

• 0.2g
• 1.8g
• 5.4g
• 14.2g

In which of the following is the entropy change positive?

• Thermal dissociation of ammonium chloride
• Reaction between an acid and a base
• Addition of concentrated acid to water
• Dissolution of sodium metal in water

If a reaction is exothermic and there is a great disorder, it means that

• the reaction is static
• the reaction is in a state of equilibrium
• there will be a large increase in free energy
• there will be a large decrease in free energy

In the preparation of oxygen by heating KClO₃in the presence of MnO2, only moderate heat is needed because the catalyst acts by

• lowering the pressure of the reaction
• increasing the surface area of the reactant
• increase the rate of the reaction
• lowering the energy barrier of the reaction

The graph above demonstrate the effect of

• surface area on the rate of reaction
• catalyst on the rate of reaction
• pressure on the rate reaction
• concentration on the rate of reaction

2H₂g) + O₂(g) ⇋ 2H₂O(g) ΔH = - ve. What happens to the equilibrium constant of the reaction above if the temperature is increased?

• it is unaffected
• it increases
• it becomes zero
• it decreases

To a solution of an unknown compound, a little dilute tetraoxosulphate (VI) acid was added with some freshly prepared iron (II) tetraoxosulphate (VI) solution. The brown ring observed after the addition of a stream of concentrated tetraoxosulphate (VI) acid confirmed the presence of

• CO
• Cl-
• SO₂
• NO₂