JAMB UTME - Chemistry - 1987
Question 1 Rapport
An element Z, contained 90% of 168Z and 10% of Z1818 its relative atomic mass is?
Détails de la réponse
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
Question 5 Rapport
Inspite of the electronic configuration, 1s22s22p2, carbon is tetraavalent because?
Détails de la réponse
both the 2s and 2p orbitals hydrodizes
Question 6 Rapport
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)
Détails de la réponse
Question 7 Rapport
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?
Détails de la réponse
Question 8 Rapport
Ethanol reacts with aqueous sodium mono-oxoio date (l) to give a bright yellow solid with a characteristic smell. The product is?
Détails de la réponse
Question 9 Rapport
Use the option above to answer this question. The structure of benzoic acid is
Détails de la réponse
Question 10 Rapport
The greater the different in electronegativity between bonded atoms, the?
Détails de la réponse
Question 11 Rapport
| 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
Détails de la réponse
Question 12 Rapport
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?
Détails de la réponse
Question 13 Rapport
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?
Détails de la réponse
Mass number = number of protons + number of neutrons
36 = 17 + X; X = 36 -17 = 19
19 neutrons and 17 protons
Question 14 Rapport
Which of the following compounds will give a precipitate with an aqueous ammoniacal solution of copper (l) chloride?
Question 15 Rapport
Local black soap is made by boiling palm oil with liquid extract of ash. The function of the ash is to provide the?
Détails de la réponse
Question 16 Rapport
In which of the following are the aqueous solutions of each of the substances correctly arranged in order to decreasing acidity?
Détails de la réponse
Question 17 Rapport
The efficiency of petrol as a fuel in high-compression internal combustion engines improves with an increase in the amount of?
Détails de la réponse
Question 18 Rapport
Which of the following water samples will have the highest titre value when titrated for the Ca2+ ions using soap solution?
Détails de la réponse
Question 19 Rapport
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?
Détails de la réponse
NaOH + HCl → NaCl + H2O moles ratio = 1/1
↔ (MaVa) / Mb x 39.45 = 0.094
Question 20 Rapport
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.
Détails de la réponse
Question 21 Rapport
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?
Détails de la réponse
Question 23 Rapport
The atomic numbers of two elements X and Y are 12 and 19 respectively. The bond of these two elements is?
Détails de la réponse
Question 24 Rapport
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?
Détails de la réponse
Question 25 Rapport
The most volatile fraction obtained from fractional distillation of crude petroleum contains?
Détails de la réponse
Question 26 Rapport
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.
Détails de la réponse
Question 27 Rapport
In the purification of town water supply, alum is used principally to?
Détails de la réponse
Question 29 Rapport
In which of the following pairs of element is allotropy exhibited by each element?
Détails de la réponse
Question 30 Rapport
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?
Question 32 Rapport
Which of the following elements will form oxide which will dissolve both in dilute HNO3 and NaOH solutions to form salts?
Détails de la réponse
Question 33 Rapport
When sodium hydroxide is heated with ammonium tetraoxosulphate (IV), the gas given off may be collected by?
Détails de la réponse
Question 34 Rapport
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)?
Détails de la réponse
