JAMB UTME - Chemistry - 1987
Pregunta 1 Informe
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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Pregunta 2 Informe
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?
Detalles de la respuesta
NaOH + HCl → NaCl + H2O moles ratio = 1/1
↔ (MaVa) / Mb x 39.45 = 0.094
Pregunta 3 Informe
An element Z, contained 90% of 168Z and 10% of Z1818 its relative atomic mass is?
Detalles de la respuesta
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
Pregunta 4 Informe
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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Pregunta 5 Informe
Inspite of the electronic configuration, 1s22s22p2, carbon is tetraavalent because?
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both the 2s and 2p orbitals hydrodizes
Pregunta 6 Informe
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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Pregunta 7 Informe
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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Pregunta 9 Informe
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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Pregunta 10 Informe
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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Pregunta 11 Informe
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?
Detalles de la respuesta
Mass number = number of protons + number of neutrons
36 = 17 + X; X = 36 -17 = 19
19 neutrons and 17 protons
Pregunta 12 Informe
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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Pregunta 13 Informe
The most volatile fraction obtained from fractional distillation of crude petroleum contains?
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Pregunta 15 Informe
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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Pregunta 17 Informe
In the purification of town water supply, alum is used principally to?
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Pregunta 18 Informe
In which of the following pairs of element is allotropy exhibited by each element?
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Pregunta 19 Informe
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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Pregunta 20 Informe
When sodium hydroxide is heated with ammonium tetraoxosulphate (IV), the gas given off may be collected by?
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Pregunta 22 Informe
The greater the different in electronegativity between bonded atoms, the?
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Pregunta 23 Informe
Use the option above to answer this question. The structure of benzoic acid is
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Pregunta 24 Informe
| 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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Pregunta 25 Informe
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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Pregunta 26 Informe
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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Pregunta 27 Informe
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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Pregunta 28 Informe
Which of the following compounds will give a precipitate with an aqueous ammoniacal solution of copper (l) chloride?
Pregunta 30 Informe
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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Pregunta 32 Informe
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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Pregunta 33 Informe
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?
Pregunta 34 Informe
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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