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Chemistry Past Questions

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4,306 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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4,306 questions

Question 1 of 20 4,306 total questions

Question 1831

jamb 1990

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

ACopper

BIron

CLead

DMercury

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Question 1832

jamb 1990

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

Aan acidic oxide

Ba basic oxide

Ca neutral oxide

Dan amphoteric oxide

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Question 1833

jamb 1990

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

Avanadium

Bplatinum

Ciron

Dcopper

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Question 1834

jamb 1990

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

APass each gas into water and test with blue litmus paper

BPass each gas into lime water

CExpose each gas to atmospheric air

DPass each gas to concentrated tetraoxosulphate (IV) acid

View Explanation & Discuss

Question 1835

jamb 1990

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

ANO₂ and O₂

BH₂O and NO₂

CNO_2' O₂ and H₂O

DNO, NO₂ and H₂O

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Question 1836

jamb 1990

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

ANO

BH ₂

CNH₃

DCl ₂

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Question 1837

jamb 1990

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?

Araising the pressure

Braising the temperature

Cadding a catalyst

Dlowering the pressure

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Question 1838

jamb 1990

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

A5 g of lumps of CacO₃ at 25°C

B5 g of powered CacO₃ at 25°

C5 g of lumps of CaCO₃ at 50°C

D5 g of powered CaCO₃ AT 50°C

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Question 1839

jamb 1990

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

Azinc has a more positive oxidation potential than iron

Bzinc has less positive oxidation potential than iron

Cbith have the same oxidation potential

Dzinc is harder than iron

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Question 1840

jamb 1990

Fe\(_2\)O\(_{3(s)}\) + 2Al\(_{(s)}\) → Al\(_2\)O\(_3\) + 2Fe\(_{(s)}\). If the heats of formation of Al\(_2\)O\(_3\) and Fe\(_2\)O\(_3\) are - 1670 kJmol\(^{-1}\) and - 822 kJmol\(^{-1}\) respectively, the enthalpy change in kJ for the reaction is ?

A+2492

B+848

C-848

D-2492

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Question 1841

jamb 1990

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

AH⁺

Bl^-

C1O^-

Dl₂

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Question 1842

jamb 1990

Cr\(_2\)O\(_7\)\(^{2-}\) + 6Fe\(^{2+}\) + 14H\(^+\) → 2Cr\(^{3+}\) +6Fe\(^{3+}\) + 7H\(_2\)O. In the above , the oxidation number of chromium changed from?

A+7 to +3

B+6 to +3

C+5 to +3

D-2 to +3

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Question 1843

jamb 1990

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

A0.40 kg

B0.20 kg

C0.06 kg

D0.04 kg

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Question 1844

jamb 1990

Which of the following is a physical change?

AThe bubbling of chlorine into water

BThe bubbling of chlorine into a jar contanining hydrogen

CThe dissolution of sodium chloride in water

DThe passing of steam over heated iron

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Question 1845

waec 1989

What is the voltage of the cell represented at Zn(s)/ Zn\(^{2+}\)(aq) //Cu\(^{2+}\)(aq) /Cu(s) given that for Cu\(^{2+}\)(aq)/ Cu (s) E\(^0\) = 0.337V and for Zn\(^{2+}\)(aq) /Zn(s)' E\(^0\) = - 0.763V?

A+0.426V

B-0.426V

C-0.337V

D-1.10V

E+1.10V

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Question 1846

waec 1989

The oxidation number of chlorine is + 1 in

AKCIO ₃

BCI ₂O ₇

CZnCI₂

DHCI

ENaCIO

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Question 1847

waec 1989

50cm\(^3\) of a saturated solution of potassium trioxonitrate (V)at 40°C contains 5.05g of the salt. What is the solubility of potassium trioxonitrate (V) at 40°C? (KNO\(_3\) = 101)

A1.0 mol dm^-3

B1.5 mol dm^-3

C2.0 mol dm^-3

D2.5mol dm^-3

E5.0mol dm^-3

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Question 1848

waec 1989

Which of the following is a condition for a spontaneous reaction?

A∆H -T is zero

B∆H-T∆ S is positive

C∆H-T∆ S is negative

D∆S is zero

E∆S is positive

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Question 1849

waec 1989

The electronic configuration of two atoms X and Y are as follows: X - 1s ² 2s ²2p ⁶3s ¹, Y -1s ²2s ²2p ⁶3s²3p ⁶4s ² which of the statements below is true of the position of X and Y in the Periodic Table?

Ax belongs to group 1, Y belongs to period 2,

Bx belongs to group 1, Y belongs to period 4

Cx belongs to group 2, Y belongs to period 1

Dx belongs to group 3, Y belongs to period 2

Ex belongs to group 3, Y belongs to period 4

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Question 1850

waec 1989

What quantity of copper will be deposited by the same quantity of electricity that deposited 9.0g of aluminum? (A = 27, Cu = 64)

A64g

B32g

C7.1g

D6.4g

E3.2g

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