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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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Past Questions

4,306 questions

Question 1 of 20 4,306 total questions

Question 2011

jamb 1983

When sodium dioxonitrate (lll) (NaNO₂) dissolves in water, ∆H is positive. The process of dissolution is

Aexothermic

Bendothermic

Cisothermal

Disomeric

Ehygroscopic

View Explanation & Discuss

Question 2012

jamb 1983

Which of the following statements is FALSE?

ACopper (ll) ion can be reduced to copper (l) ion by hydrochloric acid and zinc

BSodium metal dissolves in water giving oxygen

CNitrogen is insoluble in water

DCarbondioxide is soluble in water

Elead has a higher atomic weight than copper

View Explanation & Discuss

Question 2013

jamb 1983

Liquid X, reacts with sodium trioxocarbonate (IV) (Na₂CO₃) to give a gas which turns calcium chloride solution milky X is

ANa₂SO₄(aq)

BKl (aq)

Can alkali

Dan acid

Ea hydrocarbon

View Explanation & Discuss

Question 2014

jamb 1983

A jet plane carrying 3,000 kg of ethane burns off all the gas forming water and carbondioxide. if all the carbondioxide is expelled and all the water formed is condensed and kept on board the plane, then the gain in weight is

A1,800 kg

B900 kg

C600 kg

D2, 400 kg

E1, 200 kg

View Explanation & Discuss

Question 2015

jamb 1983

Which of the following is a neutralization reaction?

AAddition of sodium chloride solution to potassium chloride solution

BAddition of trioxonitrate (V) acid (nitric acid) to distilled water

CAddition of trioxonitrate (V) acid (nitric acid) to tetraoxosulphate (IV) acid (sulphuric acid)

DAddition of trioxonitrate (V) acid (nitric acid) to potassium trioxonitrate (V) (potassium nitrate) solution

EAddition of trioxonitrate (V) acid (nitric acid) to potassium hydroxide solution

View Explanation & Discuss

Question 2016

jamb 1983

The mass of an atom is determined by

Aits ionization potential

Bits electrochemical potential

Cthe number of protons and electrons

Dthe number of neutrons and protons

Ethe number of neutrons and electrons

View Explanation & Discuss

Question 2017

jamb 1983

Which of the following solutions will give a white precipitate with barium chloride solution and a green flame test?

ANa₂SO₄

BCuSO₄

CCaSO₄

DCaCI₂

E(NH₄)₂SO₄

View Explanation & Discuss

Question 2018

jamb 1983

A gas that can behave as a reducing agent towards chlorine and as an oxidizing agent toward hydrogen sulphide is

AO₂

BNO

CSO₂

DNH₃

ECO₂

View Explanation & Discuss

Question 2019

jamb 1983

The cracking process is very important in the petroleum industry because it.

Agives purer products

Byields more lubricants

Cyields more engine fuels

Dyields more asphalt

Eyields more candle wax

View Explanation & Discuss

Question 2020

jamb 1983

3. 06 g of a sample of potassium trioxochlorate (V) (KCIO\(_3\)) was required to make a saturated solution with 10cm\(^3\) of water at 25°C. The solubility of the salt at 25°C is [K =39, Cl = 35.5, O = 16]

A5.0 moles dm³

B3.0 moles dm³

C2.5 moles dm³

D1.0 molesv

E0.5 moles dm³

View Explanation & Discuss

Question 2021

jamb 1983

2.5 g of a hydrate barium salt gave on heating, 2.13 g of the anhydrous salt. Given that the relative molecular mass of the of the anhydrous salt is 208, the number of molecules of water of crystallization of the barium salt is

A10

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Question 2022

jamb 1983

Increasing the pressure of a gas

Alowers the average kinetic energy of the molecules

Bdecreases the density of the gas

Cdecreases the temperature of the gas

Dincreases the density of the gas

Eincreases the volume of the gas

View Explanation & Discuss

Question 2023

jamb 1983

Which of the following separation processes is most likely to yield high quality ethanol (>95%) from palm wine?

AFractional distillation without a dehydrant

Bsimple distillation with a dehydrant

Cfractional distillation with a dehydrant

Dcolumn chromatography

Eevaporation

View Explanation & Discuss

Question 2024

jamb 1983

In the preparation of some pure crystals of Cu (NO₃)₂ starting with CuO, a student gave the following statements as steps he employed. Which of these shows a flaw in his report ?

Asome CuO was reacted with excess dilute H₂SO₄

Bthe solution was concentrated

Cwhen the concentrate was cooled, crystals formed were removed by filtration

Dthe crystals were washed with very little cold water

Ethe crystals were then allowed to dry

View Explanation & Discuss

Question 2025

jamb 1983

Some metals are extracted from their ores after some preliminary treatments by electrolysis (L), some by thermal decomposition(T), some by a combination of both processes (TL). Which set-up in the following for the extraction of iron, copper, and aluminium is correct?

Alron (L), copper (L) aluminium (T)

Blron (T) copper (L) aluminium (T)

Clron (TL) copper (TL) aluminium (TL)

DIron (L) copper (T) aluminium (T)

Elron (T) copper (L), aluminium (TL)

View Explanation & Discuss

Question 2026

jamb 1983

Which of the following pair of gases will NOT react further with oxygen at a temperature between 30^oC AND 400^oC

ASO₂ and NH₃

BCO₂ and H₂

CNO₂ and SO₃

DSO₃ and NO

ECO and H₂

View Explanation & Discuss

Question 2027

jamb 1983

Which volume of 0.5 M H ₂SO₄ will exactly neutralize 20 cm ³ of 0.1 M NaOH solution?

A2.0 cm ³

B5.0 cm ³

C6.8 cm ³

D8.3 cm ³

E10.4 cm ³

View Explanation & Discuss

Question 2028

jamb 1983

Stainless steel is an alloy of

Acarbon, iron and lead

Bcarbon, iron and chromium

Ccarbon, iron and copper

Dcarbon, iron and silver

Ecarbon and iron only

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Question 2029

jamb 1983

Which of these metals, Mg, Fe, Pb and Cu will dissolve in dilute HCI?

AAll the metals

BMg ,Fe and Cu

CMg, Fe and Pb

DMg and Fe only

EMg only

View Explanation & Discuss

Question 2030

jamb 1983

In the reactions

(I) H₂ (g) + 1/2O₂(g) → H₂O(l); ∆H = -286 KJ

(II) C(s) + O₂g) → CO₂ (g); ∆H = -406 KJ the equations imply that

Amore heat is absorbed in (l)

Bmore heat is absorbed in (ll)

Cless heat is evolved in (l)

Dreaction (ll) proceeds faster than (l)

Ereaction (l) proceeds faster than (ll)

View Explanation & Discuss

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