JAMB UTME - Chemistry - 1987
Pergunta 2 Relatório
An isotope has an atomic number of 17 and a mass number of 36. Which of the following gives the correct number of neutrons and protons in an atom of the isotope?
Detalhes da Resposta
Mass number = number of protons + number of neutrons
36 = 17 + X; X = 36 -17 = 19
19 neutrons and 17 protons
Pergunta 3 Relatório
Ethanol reacts with aqueous sodium mono-oxoio date (l) to give a bright yellow solid with a characteristic smell. The product is?
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Pergunta 4 Relatório
The most volatile fraction obtained from fractional distillation of crude petroleum contains?
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Pergunta 5 Relatório
The efficiency of petrol as a fuel in high-compression internal combustion engines improves with an increase in the amount of?
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Pergunta 6 Relatório
The reaction between sulphur (IV) oxide and oxygen is represented by the equilibrium reaction 2SO2(g) + O2(g) ↔ 2SO3(g), ∆H = -196 kJ. What factor would influence increased production of SO3(g)?
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Pergunta 7 Relatório
The greater the different in electronegativity between bonded atoms, the?
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Pergunta 8 Relatório
If 24.83 cm3 of 0.15 M NaOH is titrated to its end point with 39.45 cm3 of HCl, what is the molarity of the HCl?
Detalhes da Resposta
NaOH + HCl → NaCl + H2O moles ratio = 1/1
↔ (MaVa) / Mb x 39.45 = 0.094
Pergunta 9 Relatório
An element Z, contained 90% of 168Z and 10% of Z1818 its relative atomic mass is?
Detalhes da Resposta
Mass number of Z = 16 while that of Z is 18
90 x 16 = 14.4 10 x 18 = 1.8
100 1 100 1
it relative atomic mass = 14.4 + 1.8 = 162
Pergunta 12 Relatório
A stream of air was successively passed through three tubes X, Y and Z containing a concentrated aqueous solution of KOH, red hot copper powder and fused calcium chloride respectively. What was the composition of the gas emanating from tube Z?
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Pergunta 13 Relatório
If d represents the density of a gas and K is a constant, the rate of gaseous diffusion r is related to d by the equation?
Pergunta 14 Relatório
Which of the following gases can best be used for demonstrating the fountain experiment?
I) Nitrogen (ii) Ammonia (iii) Nitrogen (I) oxide
(iv) Hydrogen chloride.
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Pergunta 15 Relatório
Local black soap is made by boiling palm oil with liquid extract of ash. The function of the ash is to provide the?
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Pergunta 16 Relatório
The solubility of Na3AsO4(H2O)12 is 38.9g per 100g H2O. What is the mass percentage of Na3AsO4 in the saturated solution?
(As = 75, Na = 23, O = 16, H = 1)
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Pergunta 18 Relatório
Use the option above to answer this question. The structure of benzoic acid is
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Pergunta 19 Relatório
Inspite of the electronic configuration, 1s22s22p2, carbon is tetraavalent because?
Detalhes da Resposta
both the 2s and 2p orbitals hydrodizes
Pergunta 20 Relatório
Which of the following water samples will have the highest titre value when titrated for the Ca2+ ions using soap solution?
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Pergunta 21 Relatório
Which of the following elements will form oxide which will dissolve both in dilute HNO3 and NaOH solutions to form salts?
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Pergunta 22 Relatório
In the purification of town water supply, alum is used principally to?
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Pergunta 23 Relatório
Magnesium ribbon was allowed to burn inside a given gas P leaving a white solid residue Q. Addition of water to Q liberated a gas which produced dense white fumes with a drop of hydrochloric acid. The gas P was?
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Pergunta 24 Relatório
In which of the following are the aqueous solutions of each of the substances correctly arranged in order to decreasing acidity?
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Pergunta 25 Relatório
Which of the following compounds will give a precipitate with an aqueous ammoniacal solution of copper (l) chloride?
Pergunta 26 Relatório
| Temp (°C) | 25 | 35 | 45 |
| Time (seconds) | 72 | 36 | 18 |
The times taken for iodine to be liberated in the reaction between sodium thiosulphate and hydrochloric acid at various temperature are as follows. These results suggest that
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Pergunta 29 Relatório
The best treatment for a student who accidentally poured concentrated tetraoxosulphate (VI) acid on his skin in the laboratory is to wash the skin with?
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Pergunta 30 Relatório
Use the option above to answer this question. Which is the correct set of results for tests conducted respectively on fresh lime juice and ethanol.
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Pergunta 31 Relatório
When water drops are added to calcium carbide in a container and the gas is passed through a jet and lifted, the resultant flame is called an?
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Pergunta 32 Relatório
In which of the following pairs of element is allotropy exhibited by each element?
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Pergunta 33 Relatório
When sodium hydroxide is heated with ammonium tetraoxosulphate (IV), the gas given off may be collected by?
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Pergunta 34 Relatório
The atomic numbers of two elements X and Y are 12 and 19 respectively. The bond of these two elements is?
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