Chemistry JAMB, WAEC, NECO AND NABTEB Official Past Questions

2206

Which of the following can be used to predict the type of bonding in HCI?

  • A. pH value
  • B. Electronegativity difference
  • C. Heat of neutralization
  • D. Heat of solution
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2207

An element which can exist in two or more forms in the same physical state, exhibits

  • A. isotopy
  • B. structural isomerism
  • C. allotropy
  • D. variable valency
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2208

An element X has an atomic number of 16. What is its most likely oxidation state in its binary compounds?

  • A. -3
  • B. -2
  • C. +2
  • D. +4
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2209

Which of the following changes is characteristic of an alpha-particle emission?

  • A. the nucleus loses two protons and two neutrons
  • B. a proton combines with an electron giving off heat
  • C. the nucleus splits into two equal parts
  • D. four neutrons are lost
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2210

Which of the following sets of elements are arranged in order of decreasing atomic size in the Periodic Table?

  • A. 6C, 4Be, 7N,8 O
  • B. 4Be,6 C,7 N,8 O
  • C. 8O, 7 N, 6C, 4Be
  • D. 7N, 8O, 6C,4Be
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2211

What is the mass number of an element having 20 neutrons, 15 protons and 15 electrons?

  • A. 15
  • B. 30
  • C. 35
  • D. 50
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2212

The electronic configuration of an element X is 1s22s 22s63p 2 3p4. It can be deduced that X

  • A. Belongs to group 6 of the Periodic Table
  • B. Belongs to group IV of the Periodic Table
  • C. has 3 unpaired electrons in its atom
  • D. has relative molecular mass of 16
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2213

Which of the following measures is not suitable for controlling water pollution?

  • A. treating industrial effluent and domestic sewage before discharge into water
  • B. Controlling the use of agrochemicals
  • C. recycling industrial and agricultural wastes
  • D. burning industrial and agricultural wastes before discharge into water ways
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2214

The process of seeding during the extraction of aluminium involves the addition of pure AI(OH)3 crystals in order to

  • A. lower the temperature
  • B. increase the concentration
  • C. facilitate the precipitation of solid
  • D. reduce the viscosity of the solution
View Answer & Discuss WAEC 2004
2215

Which of the following pollutants is biodegradable?

  • A. Domestic sewage
  • B. Metal scraps
  • C. Radioactive waste
  • D. Plastic foil
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2216

Which of the following is required in an experiment to determine the enthalpy of solution of anhydrous CuSO? l. Mass of the anhydrous CuSO 4 II. Volume of water in which the CuSO4 is dissolved lll. lnitial temperature of water lV. Final temperature of the solution

  • A. l and ll only
  • B. lll and IV only
  • C. ll, lll, and IV only
  • D. l, ll, lll, and IV only
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2217

What is the product Cx Hy in the following equation? \(C_{10}H_{22}\) → \(C_{8}H_{18}\) + CxHy

  • A. butene
  • B. octane
  • C. ethene
  • D. decane
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2218

WHICH OF THE FOLLOWING PETROLEUM FRACTIONS YIELDS VASELINE AND PARAFFIN WAX ON REDISTILLATION?

  • A. DIESEL OIL
  • B. LUBRICATION OIL
  • C. PETROL
  • D. KEROSENE
View Answer & Discuss WAEC 2004
2219

Which of the following reactions will be affected by change in pressure at equilibrium?

  • A. X(g) + Y(g) ⇌ W(g) + Z(g)
  • B. X(g) + 2Y(g) ⇌W(g) + Z(g)
  • C. 2X(g) ⇌ W(g) + Z(g)
  • D. 2Y(g) ⇌ W(g) + Z(g)
View Answer & Discuss WAEC 2004
2220

The key factor to be considered in siting a chemical industry is

  • A. favourable climatic conditions
  • B. the availability of space to store raw materials
  • C. its nearness to other industrial establishments
  • D. its nearness to the source of raw materials
View Answer & Discuss WAEC 2004
2221

What is the change in the oxidation number of 1 in the reaction represented by the following equation? 51 -1(aq) + 6H+(aq) + 1O3(aq) → 312(g) + 3H2O(l)

  • A. -5 to -3
  • B. -1 to 0
  • C. + 5 to + 0
  • D. -1 to + 2
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2222

Which of the following statements is true of an endothermic reaction? I. Heat is absorbed from the surrounding II. The heat content of the products is more than that of the reactants III. The enthalpy change is positive IV. The surrounding is at a lower temperature than the system.

  • A. l only
  • B. l and ll only
  • C. l,ll and lll only
  • D. l, ll, lll and lV
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2223

The condensation of several amino acid molecules gives

  • A. long chain alkanoic acids
  • B. secondary alkanols
  • C. alkanoates
  • D. proteins
View Answer & Discuss WAEC 2004
2224

When ammonium trioxocarbonate (IV) solution is added to separate solutions of calcium, zinc and sodium salt precipitate could be formed in the case of

  • A. calcium only
  • B. zinc only
  • C. calcium and znic only
  • D. sodium and zinc only
View Answer & Discuss WAEC 2004
2225

Consider the cell represented below: Zn/Zn2+(aq) // Cu2+(aq) / Cu(s). Which of the following statements is correct about the cell

  • A. Zn is oxidized to Zn2+
  • B. Cu is oxidized to Cu2+
  • C. It is an electrolytic cell
  • D. each single line represents a salt bridge
View Answer & Discuss WAEC 2004
2226

If 60 cm3 of gas is heated from 27oC TO 50oC, what is the new volume of the gas at constant pressure?

  • A. 32.4cm 3
  • B. 55.7cm3
  • C. 64.6cm3
  • D. 111.1cm3
View Answer & Discuss WAEC 2004