JAMB Chemistry Past Questions & Answers - Page 9

Radon is a radioactive noble gas and is produced as a decay product of uranium and thorium in the Earth's crust. It is colorless, odorless, and tasteless, making it potentially hazardous when it accumulates in enclosed spaces.

When the temperature is decreased in a reversible reaction, the equilibrium shifts in the direction that produces heat (exothermic direction). For an exothermic reaction, this means the equilibrium position shifts to the right, favoring the forward reaction.

Hard water is water with high concentrations of dissolved ions, in particular calcium and magnesium ions

The air in Earth's atmosphere is made up of approximately 78 percent nitrogen and 21 percent oxygen. Air also has small amounts of other gases, too, such as carbon dioxide, neon, and hydrogen.

To make a fixed amount of a dilute solution from a stock solution,

use the formula: C1V1 = C2V2 

where: V1 = Volume of stock solution needed to make the new solution. 

C1 = Concentration of stock solution.

V2 = Final volume of new solution.

C2 = Final  concentration of stock solution

2 * 10 = 0.5 * V2

20 = 0.5V2

\(\frac{20}{0.5}\) = V2

= 40dm\(^3\)

Alkanes are very useful as fuels.

Isomers of Butene: are But-1-ene, But-2-ene, 2-Methylpropene or 2-methylprop-1-ene

There are 4 bond pairs in CO₂ and no lone pairs are there.

Pre-heated air at about 600ºC is blown into the furnaces from the bottom through the tuyeres.

Cast iron + haematite = wrought iron