JAMB UTME - Chemistry - 1987

Stainless steel is an alloy of?

Maelezo ya Majibu

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

Maelezo ya Majibu

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?

Maelezo ya Majibu

r = k /√d

In the purification of town water supply, alum is used principally to?

Maelezo ya Majibu

Use the option above to answer this question. The structure of benzoic acid is

Maelezo ya Majibu

In which of the following pairs of element is allotropy exhibited by each element?

Maelezo ya Majibu

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?

Maelezo ya Majibu

Mass number = number of protons + number of neutrons
36 = 17 + X; X = 36 -17 = 19
19 neutrons and 17 protons

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?

Maelezo ya Majibu

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.

Maelezo ya Majibu

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?

Maelezo ya Majibu

The greater the different in electronegativity between bonded atoms, the?

Maelezo ya Majibu

Which of the following elements will form oxide which will dissolve both in dilute HNO3 and NaOH solutions to form salts?

Maelezo ya Majibu

Alloys are best prepared by?

Maelezo ya Majibu

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?

Maelezo ya Majibu

NaOH + HCl → NaCl + H2O moles ratio = 1/1
↔ (MaVa) / Mb x 39.45 = 0.094

Local black soap is made by boiling palm oil with liquid extract of ash. The function of the ash is to provide the?

Maelezo ya Majibu

Complete oxidation of propan -1- ol gives?

Maelezo ya Majibu

In which of the following are the aqueous solutions of each of the substances correctly arranged in order to decreasing acidity?

Maelezo ya Majibu

Corrosion is exhibited by

Maelezo ya Majibu

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.

Maelezo ya Majibu

The atomic numbers of two elements X and Y are 12 and 19 respectively. The bond of these two elements is?

Maelezo ya Majibu

The efficiency of petrol as a fuel in high-compression internal combustion engines improves with an increase in the amount of?

Maelezo ya Majibu

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?

Maelezo ya Majibu

Inspite of the electronic configuration, 1s22s22p2, carbon is tetraavalent because?

Maelezo ya Majibu

both the 2s and 2p orbitals hydrodizes

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)

Maelezo ya Majibu

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)?

Maelezo ya Majibu

Which of the following water samples will have the highest titre value when titrated for the Ca2+ ions using soap solution?

Maelezo ya Majibu

Which of the following compounds will give a precipitate with an aqueous ammoniacal solution of copper (l) chloride?

Maelezo ya Majibu

HC = C-CH2CH3

Ethanol reacts with aqueous sodium mono-oxoio date (l) to give a bright yellow solid with a characteristic smell. The product is?

Maelezo ya Majibu

The most volatile fraction obtained from fractional distillation of crude petroleum contains?

Maelezo ya Majibu

Oil spillage in ponds and creeks can be cleaned up by?

Maelezo ya Majibu

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?

Maelezo ya Majibu

When sodium hydroxide is heated with ammonium tetraoxosulphate (IV), the gas given off may be collected by?

Maelezo ya Majibu

Synthetic rubber is made by polymerization of?

Maelezo ya Majibu

An element Z, contained 90% of 168Z and 10% of Z1818 its relative atomic mass is?

Maelezo ya Majibu

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