JAMB UTME - Chemistry - 1987

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

Antwoorddetails

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?

Antwoorddetails

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

Synthetic rubber is made by polymerization of?

Antwoorddetails

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

Antwoorddetails

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

Antwoorddetails

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

Antwoorddetails

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

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

Antwoorddetails

HC = C-CH2CH3

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?

Antwoorddetails

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.

Antwoorddetails

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?

Antwoorddetails

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

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

Antwoorddetails

Corrosion is exhibited by

Antwoorddetails

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.

Antwoorddetails

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

Antwoorddetails

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?

Antwoorddetails

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

Antwoorddetails

Alloys are best prepared by?

Antwoorddetails

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

Antwoorddetails

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

Antwoorddetails

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

Antwoorddetails

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

Antwoorddetails

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

Antwoorddetails

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?

Antwoorddetails

r = k /√d

Stainless steel is an alloy of?

Antwoorddetails

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)

Antwoorddetails

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?

Antwoorddetails

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

Antwoorddetails

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

Antwoorddetails

Complete oxidation of propan -1- ol gives?

Antwoorddetails

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?

Antwoorddetails

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

Antwoorddetails

both the 2s and 2p orbitals hydrodizes

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)?

Antwoorddetails

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

Antwoorddetails

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

Antwoorddetails