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Chemistry Past Questions

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137 questions JAMB 2505 WAEC 1623 NECO 168 CUSTOM 10

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137 questions

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Question 51

jamb 2018

The salt that reacts with dilute hydrochloric acid to produce a pungent smelling gas which decolourizes acidified purple potassium tetraoxomanganate (VII) solution is

ANa\(_2\)SO\(_4\)

BNa\(_2\)SO\(_3\)

CNa\(_2\)S

DNa\(_2\)CO\(_3\)

View Explanation & Discuss

Question 52

jamb 2018

(I). 3CuO(s) + 2NH3(g) -----> 3Cu(s) + 3H2O(l) + N2(g)
(II). 2NH3(g) + 3Cl2(g) -----> 6HCl(g) + N2(g)
(III). 4NH3(g) + 3O2(g) -----> 6H2O(l) + N2(g)
The reactions represented by the equations above demonstrate the

Abasic properties of ammonia

Bacidic properties of ammonia

Creducing properties of ammonia

Doxidizing properties of ammonia

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Question 53

jamb 2018

mE + nF -----> pG + qH
In the equation shown, the equilibrium constant is given by?

A\(\frac{[E]^m[F]}{[G]^p[H]^q}\)

B\(\frac{[E][F]}{[G][H]}\)

C\(\frac{[G]^p[H]^q}{[E]^m[F]^n}\)

D\(\frac{[G][H]}{[E][F]}\)

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Question 54

jamb 2018

Beryllium and Aluminium have similar properties because they

Aare both metals

Bbelong to the same group

Cbelong to the same period

Dare positioned diagonally to each other

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Question 55

jamb 2018

The radio isotope used in industrial radiography for the rapid checking of faults in welds and casting is?

Acarbon-14

Bphosphorus-32

Ccobalt-60

Diodine-131

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Question 56

jamb 2018

How many atoms are present in 6.0g of magnesium? [Mg = 24, N.A = 6.02 x 10 \(^{23}\)mol]

A1.20 x 10\(^{22}\)

B2.4 x 10\(^{22}\)

C1.51 x 10\(^{23}\)

D3.02 x 10\(^{22}\)

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Question 57

jamb 2018

What is the concentration of a solution containing 2g of NaOH in 100cm3 of solution? [Na = 23, O =16, H = 1]

A0.40 moldm\(^{-3}\)

B0.50 moldm\(^{-3}\)

C0.05 moldm\(^{-3}\)

D0.30 moldm\(^{-3}\)

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Question 58

jamb 2018

An aqueous solution of a metal salt, M. gives a white precipitate with NaOH which dissolves in excess NaOH. With aqueous ammonia, the solution of M also gives a white precipitate which dissolves in excess ammonia Therefore the cation in M is

AZn

BCa

CAl

DPb

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Question 59

jamb 2018

The lUPAC name for

A1-methyl pentane

B3-methylbutane

C2-methylbutane

D1-dimethyl propane

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Question 60

jamb 2018

If one of the following oxides is heated with hydrogen or carbon using a bunsen burner. it is not reduced to the metal, Which one is it?

Alead oxide

BMagnesium oxide

CCopper oxide

DTin oxide

View Explanation & Discuss

Question 61

jamb 2018

What volume of oxygen will remain after reacting 8cm\(^3\) of hydrogen gas with 20cm\(^3\) of oxygen gas?

A10cm\(^3\)

B12cm\(^3\)

C14cm\(^3\)

D16cm\(^3\)

View Explanation & Discuss

Question 62

jamb 2018

The number of electrons in the valence shell of an element of atomic number 14 is?

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Question 63

jamb 2018

Suitable reagents for the laboratory preparation of nitrogen are

Asodium dioxonitrate(III) and ammonium chloride

Bsodium trioxonitrate(V) and ammonium chloride

Csodium chloride and ammonium trioxonitrate(V)

Dsodium chloride and ammonium di-ozonitrate(III)

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Question 64

jamb 2018

A quantity of electricity liberates 3.6g of Silver from its salt. What mass of aluminium Will be liberated from its salt by the same quantity of electricity? [Al = 27, Ag = 108].

A2.7g

B1.2g

C0.9g

D0.3g

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Question 65

jamb 2018

Methanoic acid mixes with water in all proportions and has about the same boiling point as water. Which of the following methods would you adopt to obtain pure water from a mixture of Sand, water and methanoic acid?

AExtractive distillation

BFiltration followed by distillation

CNeutralization with sodium hydroxide followed by distillation

DNeutralization with sodium hydroxide followed by filtration

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Question 66

jamb 2018

In the preparation of oxygen by heating KCIO\(_3\) , in the presence of MnO\(_2\) only moderate heat is needed because the catalyst acts by \(_2\)

Alowering the pressure of the reaction

Bincreasing the surface area of the reaction

Cincreasing the rate of the reaction

Dincreasing the energy barrier of the reaction

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Question 67

jamb 2018

Which of the following pairs of substances will react further with oxygen to form a higher oxide?

ACO\(_2\) and H\(_2\)O

BNO and H\(_2\)O

CCO and CO\(_2\)

DSO\(_2\) and NO

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Question 68

jamb 2018

The boiling of fat and aqueous caustic soda is referred to as

Ahydrolysis

Besterification

Cacidification

Dsaponification

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Question 69

jamb 2018

In the shown experiment (Fig. 1) the litmus paper will initially

Abe bleached

Bturn green

Cturn red

Dturn blue

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Question 70

jamb 2018

If 1 litre of 2.2M sulphuric acid is poured into a bucket containing 10 litres of water and the resulting solution mixed thoroughly, the resulting sulphuric acid concentration will be

A2.2M

B1.1M

C0.2M

D0.11M

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