2018 - JAMB Chemistry Past Questions and Answers - page 8
An element X forms the following compounds with chlorine; XCl\(_4\), XCl\(_3\), XCl\(_2\). This illustrates the
The law of multiple proportion states that when element A and B combine to form more than one chemical compound then the various masses of sample A react with a fixed mass of sample B are in a simple multiple ratio.
The hydrogen ion concentration of a sample of orange juice is 2.0 X 10\(^{-11}\)moldm\(^{-3}\). What is its p\(^{OH}\)? [log102 = 0.3010]
p\(^{OH}\) = -Log [OH\(^-\)]
[OH\(^-\) ] = 2.0 X 10\(^{-11}\)moldm\(^{-3}\)
p\(^{OH}\) = -Log [2.0 X 10\(^{-11}\)]
p\(^{OH}\) = 10.70
2SO\(_2\) \(_{(g) }\)+ O\(_2\) \(_{(g) }\) ↔ 2SO\(_3\)\(_{(g) }\) ΔH = -395.7kJmol\(^{-1}\)
In the equation, an increase in temperature will shift the equilibrium position to the
The end products of burning a candle in the atmosphere are water and
The collision theory explains reaction rates in terms of
The presence of ammonia gas in a desiccator can exclusively be removed by
Ammonia gas can be removed from a dessicator by adding a conc. H2SO4 so as to neutralize it since ammonia gas is basic.
Aluminium does not react with either dilute or concentrated trioxonitrate (V) acid because
Aluminium doesn’t react with either dilute or concentrated trioxonitrate (V) acid because an insoluble oxide is formed on its surface which renders it passive. It will depend on the concentration of the nitric acid used…. Although aluminium reacts with dilute nitric acid to produce aluminium nitrate and hydrogen gas, concentrated (>60%) nitric acid is such a powerful oxidising agent that it instantly causes a thin layer of aluminium oxide to coat the surface of the aluminium
Which of these sources of water may likely contain the least concentration of Ca\(^{2+}\) and Mg\(^{2+}\)?
The conductivity of an acid solution depends on the
The conductivity of a solution depends on the number of charge carriers (the concentrations of the ions), the mobility of the charge carriers and their charge. Theoretically, conductivity should increase in direct proportion to concentration.