JAMB UTME - Chemistry - 1984

Ver Resposta

Pergunta 2 Relatório

Naphthalene when heated melts at 354 K (81 oC). At this temperature the molecules of naphthalene

decompose into smaller molecules

change their shape

are oxidized by atmospheric oxygen

contract

become mobile as the inter molecular forces are broken

Ver Resposta

Pergunta 3 Relatório

20 cm 3 of hydrogen gas are sparked with 20cm 3 of oxygen gas in an endimoeter at 373k (100 oC) and 1 atmosphere. The resulting mixture is cooled to 298 K (25 oC) and passed over calcium chloride. The volume of the residual gas is

40 cm 3

20 cm 3

30 cm 3

10cm 3

5cm 3

Ver Resposta

Pergunta 4 Relatório

The balanced equation for the reaction of tetraoxosulphate(VI)acid with aluminium hydroxide to give water and aluminium tetraoxosulphate(VI) is

H2SO4 + Al(OH)2

\to

2H2O + AlSO4

3H2SO4 + 2Al(OH)3

\to

6H2O + Al2(SO4)3

3H2SO4 + 2AlH

\to

6H2O + Al(SO4)3

H2 SO4 + 2Al(OH)3

\to

Al(SO4)3

H2SO4 + Al(OH)3

\to

H2O + Al2(SO4)3

Ver Resposta

Pergunta 5 Relatório

Lime - water, which is used in the laboratory for the detection of carbon(iv)oxide is an aqueous solution of

Ca(OH)2

CaCO3

CaHCO3

CaSO4

N2CO3

Ver Resposta

Pergunta 6 Relatório

For the reaction 2Fe3+ 2I- $\to$ 2Fe2+ + I2, which of the following statements is TRUE?

Fe is oxidized to Fe3+

Fe3+ is oxidized to Fe2+

I- is oxidized to I2

I- is reduced to I2

I- is displacing an electron from Fe3+

Electrolysis

Ver Resposta

Pergunta 7 Relatório

Use the diagram above to answer this question.

Which of the following represents a carboxylic acid?

A

B

C

D

E

Periodic Chemistry (Ghana Only)

Ver Resposta

Pergunta 8 Relatório

Use the diagram above to answer this question.

Which of the following structural formula is NOT isomeric with the others?

A

B

C

D

E

Ver Resposta

Pergunta 9 Relatório

Which of the following statements is NOT correct about all four of the acids: HBr, HNO3, H 2CO3 and H2SO4? They

dissolve marble to liberate CO

have a PH less than 7

Turn blue litmus red

neutralize alkalis to form salt

react with magnesium to liberate hydrogen

Acids, Bases And Salts

Ver Resposta

Pergunta 10 Relatório

Water is said to be 'hard' if it

easily forms ice

has to be warmed before sodium chloride dissolves in it

froms an insoluble scum with soap

contains nitrates

contains sodium ions

Water

Ver Resposta

Pergunta 11 Relatório

An organic compound with a vapour density 56.5 has the following percentage composition:C =53.1% N = 12.4%, O = 28.3%, H = 6.2%. The molecular formula of the compound is

Relative atomic masses: N = 14, O = 16, C = 12, H = 1 )

C3H6O2N

C5H6O2N

(C5H7O2N)1/2

C5H7O2N

(C5H7O2N)2

Chemistry Of Carbon Compounds (Ghana Only)

Solubility Of Subtances (Nigeria Only)

Ver Resposta

Pergunta 12 Relatório

In dilute solution the heat of the reaction NaOH + HCl = NaCl + H2O is - 57.3kJ. Therefore the heat of the reaction 2NaOH + H2SO4 $\to$ Na2SO4 + 2H2O is

+ 28.65 kJ

- 28.65KJ

+ 57.3KJ

- 114.6 KJ

- 229.2 KJ

Detalhes da Resposta

NaOH + HCl = NaCl + H2O $Δ$ H = -57.3kJ

Heat of reaction of 2NaOH + H2O4

NaSO4 + H2O is

= 57.3 x 2 = -114.6 kJ

Read lesson note on Kinetic Theory Of Matter And Gas Laws (JAMB)

Ver Resposta

Pergunta 13 Relatório

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 cartion in M is

Zn ++

Ca++

Ai+++

Pb++

Cu++

Acids, Bases And Salts

Ver Resposta

Pergunta 14 Relatório

Alkanes

are all gases

have the general formula CnH2n + 2O

contain only carbon and hydrogen

are usually soluble in water

are usually active compounds

Ver Resposta

Pergunta 15 Relatório

If the cost of electricity required to deposit 1 g of magnesium is ₦5.00, how much would it cost to deposit 10g of aluminium?

₦10.00

₦27.00

₦44.44

₦66.67

₦33.33

Stoichiometry And Chemical Reactions

Ver Resposta

Pergunta 16 Relatório

Alkaline hydrolysis of naturally occurring fats and oils yields

fats and acids

soaps and glycerol

margarine and butter

esters

detergents

Acids, Bases And Salts

Ver Resposta

Pergunta 17 Relatório

The name of the compound above is

acetic acid

propanal

propanol

ethanoic acid

propanoic acid

Acids, Bases And Salts

Ver Resposta

Pergunta 18 Relatório

A piece of sea shell, when dropped into a dilute solution of hydrochloric acid, produces a colourless, odourless gas which turns clear limewater milky. The sea shell contains

sodium chloride

ammonium nitrate

calcium carbonate

calcium chloride

magnesium chloride

Acids, Bases And Salts

Ver Resposta

Pergunta 19 Relatório

Which of the following statements is INCORRECT?

Fractional distillation of crude petroleum will give the folloing hydrocarbon fuels in order of increasing boiling point

Butane < petrol < kerosene of polythene.

Both but-1-ene and but-1-yne will decolorize bromine readily

but-2-ene will react with chlorine to form 2,3-dichlorobutane

calcuim carbide will react with water to form any alkyne

Ver Resposta

Pergunta 20 Relatório

In which of the following reactions does hydrogen peroxide act as a reducing agent?

H2S + H2O2

\to

S + 2H2O

PbSO3 + H2O2

\to

PbSO4 + H2O

2I+ 2H+ + H2O2

\to

I2 + 2H2O

PbO2 + 2HNO3 + H2O2

\to

Pb(NO3)2 + 2H2O + O2

SO2 + H2O2

\to

H2SO4

Oxidation And Reduction

Ver Resposta

Pergunta 21 Relatório

The hybridization of the carbon atom in ethyne is

sp 4

sp 3

sp2

sp

s

Ver Resposta

Pergunta 22 Relatório

Which of the curves shown in the figure given represents the relationships between the volume(V) and pressure(P) of an ideal gas at constant temperature?

1

2

3

4

1 and 3

Ver Resposta

Pergunta 23 Relatório

Which of the following mixtures would result in a solution of pH greater than 7?

25.00 cm3 of 0.05 M H2SO4 and 25.00cm3 of 0.50 M Na2CO3

25.00 cm3 of 0.05 M H2SO4 and 25.00 cm3 of 0.10 M NaHCO3

25.00 cm3 of 0.11 MH2SO4 and 25.00cm3 0. 10 M NaOH

25.00cm3 of 0.11 MH2 SO4 and 50.00 cm3 of 0.05 M NaOH

25.00cm3 of 0.25 M H2SO4 and 50.00cm3 of 0.20 M NaOH

Ver Resposta

Pergunta 24 Relatório

The diagram above (Fig.3) shows the energy profile for the reaction A + B + = C + D From this diagram, it is clear that the reaction is

spontaneous

isothermal

adiabatic

exothermic

endothermic

Energy Changes

Ver Resposta

Pergunta 25 Relatório

The solubility curves of four substances are shown in the figure above. Which of the four substances would crystallize from a saturated solution cooled from 353K(80oC)to 323K(50C)?

P and Q

P and R

P and S

R and S

Q and R

Solubility

Ver Resposta

Pergunta 26 Relatório

A molar solution of caustic soda is prepared by dissolving

40 g NaOH in 100 g of water

40 g NaOH in 1000 g of water

20 g NaOH in 500 of solution

20 g NaOH in 1000 g of solution

2o g NaOH in 80 g of solution

Acids, Bases And Salts

Ver Resposta

Pergunta 27 Relatório

From the reactions : ZnO + Na2O $\to$ NaZnO and ZnO + CO2 $\to$ ZnCO3 it may be concluded that zinc oxide is

neutral

basic

acidic

amphoteric

a mixture

Chemistry Of Carbon Compounds (Ghana Only)

Chemical Combination

Ver Resposta

Pergunta 28 Relatório

The function of conc. H2SO4 in the esterification of ethanoic acid with ethanol is to

serve as a dehydrating agent

serve as a solvent

act as a catalyst

prevent any side reaction

serve as an oxidizing agent

Acids, Bases And Salts

Ver Resposta

Pergunta 29 Relatório

Which of the following electrodes is used in electrolysis of bauxite (Al2O3) in molten cryolite?

Steel electrodes

Carbon electrodes

Mercury electrodes

Carbon anode and steel cathode

Carbon cathode and stell anode

Electrolysis

Ver Resposta

Pergunta 30 Relatório

If an excess of a liquid hydrocarbon is poured into a jar of chlorine, and the sealed jar is then exposed for several hours to bring sunlight, all the chlorine gas is consumed. The hydrocarbon is said to have undergone

a polymerization reaction

an isomerization reaction

an addition reaction

a substitution reaction

a reduction reaction

Ver Resposta

Pergunta 31 Relatório

Which of the following statements is NOT true of carbon monoxide?

CO is poisonous

CO is readily oxidized at room temperature by air to form CO2

CO may be prepared by reducing CO2 mixed with coke heated to about 1000oC

CO may be prepared by heating charcoal with a limited amount of O2

CO is a good reducing agent

Ver Resposta

Pergunta 32 Relatório

When the kerosene fraction from petrol is heated at high temperature, a lower boiling liquid is obtained. This process is known as

polymerization

refining

hydrogenation

cracking

Solubility

Ver Resposta

Pergunta 33 Relatório

Which among the elements 1. Carbon 2. Oxygen 3. Copper 4. Bromine 5. Zinc, will NOT react with either water or steam?

1 and 2

2 and 3

3 and 4

1, 2, and 3

2, 3, and 5

Non-metals And Their Compounds

Ver Resposta

Pergunta 34 Relatório

Nitrogen can best be obtained from a mixture over oxygen and nitrogen by passing the mixture over

potassium hydroxide

heated gold

heated magnesium

heated phosphorus

calcium chloride

Chemical Combination

Ver Resposta

Pergunta 35 Relatório

At S. T. P how many litres of hydrogen can be obtained from the reaction of 500 cm3 of 0.5 M H 2SO 4 with excess zinc metal?

(Gram molecular volume of H2 = 22. 4 dm 3)

22.4 dm 3

11 . 2 dm 3

6. 5 dm 3

5. 6 dm 3

0. 00 dm 3

Stoichiometry And Chemical Reactions

Ver Resposta

Pergunta 36 Relatório

Sodium hydroxide (NaOH) pellets are

deliquescent

hygroscopic

efflorescent

hydrated

fluorescent