Chemistry JAMB, WAEC, NECO AND NABTEB Official Past Questions

316

Determine the quantity of electricity used when a current of 0.20 amperes is passed through an electrolytic cell for 60 minutes.

  • A. 12C
  • B. 120C
  • C. 360C
  • D. 720C
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317

The products of the electrolysis of dilute sodium chloride using carbon electrodes are

Anode Cathode

  • A. chlorine and sodium.
  • B. oxygen and hydrogen.
  • C. chlorine and hydrogen.
  • D. hydrogen and oxygen.
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318

If 60 g of M combines with 24 g of oxygen, what would the empirical formula of the oxide be?

( molar mass of M = 120, O = 16)

  • A. MO
  • B. MO\(_{2}\)
  • C. MO\(_{3}\)
  • D. MO\(_{4}\)
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319

Which of the following statements about the standard hydrogen electrode is not correct?

  • A. The hydrogen gas is at a pressure of 1 atmosphere
  • B. A solution containing 1 mol dm-3 of H+ (aq) ions is used
  • C. A platinum electrode is used
  • D. The temperature is kept at 20 °C
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320

Alkanols can be manufactured from alkenes by the initial reaction of alkenes with

  • A. bromine in tetrachloromethane
  • B. concentrated tetraoxosulphate(VI) acid
  • C. aqueous potassium tetraoxomanganate(VII).
  • D. sodium hydroxide solution.
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321

Which of the following compounds would react rapidly with bromine?

  • A. Benzene
  • B. Hexane
  • C. Hexene
  • D. Hexanol
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322

What amount of electricity is required to deposit one mole of aluminium from a solution of AlCl3?

  • A. One Faraday
  • B. One ampere
  • C. Three Faradays
  • D. Three amperes
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323

The following compounds are condensation polymers except

  • A. nylon
  • B. protein
  • C. starch
  • D. polyethene
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324

The cleansing effect of soap is low in acidic water because of

  • A. the formation of unionized fatty acid.
  • B. increase in the pH of the soap molecules.
  • C. anti-biodegradable effect of hydrogen ions
  • D. the hardness of the acidic water.
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325

Which of the following sugars is a product of the condensation of monosaccharides?

  • A. galactose
  • B. maltose
  • C. glucose
  • D. fructose
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326

The by-product of fermentation of sugar is

  • A. carbon(IV) oxide.
  • B. ethanoic acid.
  • C. propanol
  • D. propan-1, 2, 3- triol.
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327

(a) Describe the observation that would be made when—–

i. Sulphur is heated from room temperature till 1190C
ii. 50% trioxonitrate(V) acid acts on copper tunings

 

(b)i. State two gaseous pollutants that can be generated by burning coal.

ii. What gas is responsible for most of the explosions in coal mines?

iii. The mining of coal leads to environmental pollution. State two environmental effects of the mining activity.

iv. Explain briefly why coal burns more easily when it is in pieces than in lump form

v. Name the non-volitile residue after the destructive distillation of coal

 

(c)i. Describe a chemical test for water

ii.a. State the effect of boiling a temporary hard water
b. State the effect of adding sodium trioxocarbonate(IV) crystals to permanent hard water

iii. Write an equation for the process of boiling a temporary hard water

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328

(a)i. State two conditions used in the Haber process

ii. Explain briefly the effect of increasing the pressure on the rate of reaction in the Haber process.

(b)i. A mixture of nitrogen(IV) oxide and oxygen is bubbled into warm water to produce
trioxonitrate(V) oxide, write a balanced chemical equation for the reaction.

ii. Using a balanced chemical equation only, explain what would happen if nitrogen(IV) oxide is bubbled into warm water.

iii. 

Compare the gases evolved when trioxonitrate(V) acid decomposes under each of the following properties:

i. pH
ii. Solubility in water

iii. Reaction with carbon(II) oxide

(c)i. Name two oxides of sulphur

ii. Write a balanced equation for the reaction between each of the named oxides(Sulphur(IV) oxide, Sulphur (VI) oxide) and water

(d)i. Name one calcium compound

a, Used to dry ammonia gas
b. Used in the manufacture of cement
c. That causes hardness in water
d. Name one calcium compound

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329

(a)i.  Define an acid according to the Lewis concept

ii. Give one example of a Lewis acid

(b) Explain salting out in soap preparation

(c) State the reagent and condition necessary for the following conversion
H−C≡C−H→Ag−C≡C−Ag

(d) What is the percentage abundance of an isotope?

(e)i. Why does the element with atomic number 18 not have an oxide?

ii. Explain why chlorine(I) oxide has a low melting point

(f). Describe a test to distinguish between concentrated HNO3 and concentrated H2SO4

(g) State two differences between an electrochemical cell and an electrolytic cell

(h) How does the trend in ionization energy affect the reactivity of group 1 elements?

(i).Define the term molecular formula

(j) State which of the gases H2 and NH3 would deviate more from ideal behaviour. Give reasons for the answer stated above

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330
GAS CO\(_2\) N\(_2\)

O\(_2\)

% BY VOLUME 4 72 24

The above table shows the compositions of the atmosphere of planet X. Which of these gases are present in higher percentages on earth?

  • A. CO\(_2\) and O\(_2\)
  • B. N\(_2\) and CO\(_2\)
  • C. CO\(_2\), O\(_2\) and N\(_2\)
  • D. O\(_2\) and N\(_2\)
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331

What volume of (dm\(^3\)) of water will be added to 10dm\(^3\) of 2.0 mol/dm\(^3\) HCL acid solution to give a final solution of 0.5 mol/dm\(^3\)?

  • A. 30
  • B. 40
  • C. 20
  • D. 50
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332

Alkanes are used mainly?

  • A. in the textile industry
  • B. in the hydrogenation of oils
  • C. as domestic and industrial fuels
  • D. as fine chemicals
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333

2-methylprop-1-ene is a structural isomer of?

  • A. But-1-yne
  • B. 2-methyl But-1-ene
  • C. 3-methyl prop-1-yne
  • D. But-2-ene
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334

How many bonding pair are present in carbon(iv)oxide? 

  • A. 4
  • B. 3
  • C. 2
  • D. 1
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335

In the extraction of iron, hot air is introduced into the blast furnace through?

  • A. valves
  • B. open-hearths
  • C. arcs
  • D. tuyeres
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336

Wrought iron is obtained by heating cast iron in a furnace with?

  • A. magnetite
  • B. haematite
  • C. carbon(ii)oxide
  • D. calcium trioxosilicate(iv)
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