2022 - JAMB Chemistry Past Questions and Answers - page 4
H\(^+\) + OH\(^-\) → H\(_2\)O
What does the equation above illustrate?
precipitation
hydration
hydrolysis
neutralization
A neutralization reaction is a chemical reaction in which an acid and base react quantitatively to form salt and water as products.
The reaction of an acid and a base to form water and a salt involves the combination of H+ ions and OH- ions to generate water.
Electrons enter into orbitals in order of increasing energy as exemplified by?
1S\(^2\)2S\(^2\)2PX\(^2\)2py\(^2\)2pz\(^0\)3s\(^0\)
1S\(^2\)2S\(^2\)2PX\(^2\)2py\(^1\)2pz\(^1\)3s\(^0\)
1S\(^2\)2S\(^2\)2PX\(^1\)2py\(^1\)2pz\(^1\)3s\(^1\)
1S\(^2\)2S\(^2\)2PX\(^2\)2py\(^2\)2pz\(^0\)3s\(^1\)
Wrought iron is obtained by heating cast iron in a furnace with?
magnetite
haematite
carbon(ii)oxide
calcium trioxosilicate(iv)
In the extraction of iron, hot air is introduced into the blast furnace through?
valves
open-hearths
arcs
tuyeres
Pre-heated air at about 600ºC is introduced into the blast furnace from the bottom through the tuyeres.
How many bonding pairs are present in carbon(iv)oxide?
4
3
2
1
2-methylprop-1-ene is a structural isomer of?
But-1-yne
2-methyl But-1-ene
3-methyl prop-1-yne
But-2-ene
Isomers of Butene:
- But-1-ene
- But-2-ene
- Isobutylene (or 2-methylpropene or 2-methylprop-1-ene)
Alkanes are used mainly for ___?
in the textile industry
in the hydrogenation of oils
as domestic and industrial fuels
as fine chemicals
Alkanes are saturated hydrocarbons that burn readily in the air with a blue non-sooty flame to release a lot of heat and light energy. This is one of the reasons they are mainly used for fuels.
What volume of (dm\(^3\)) of water will be added to 10dm\(^3\) of 2.0 mol/dm\(^3\) HCL acid solution to give a final solution of 0.5 mol/dm\(^3\)?
30
40
20
50
For a fixed amount of a dilute solution from a stock solution: C1V1 = C2V2
where:
- V1 = Volume of stock solution needed to make the new solution
- C1 = Concentration of stock solution
- V2 = Final volume of the new solution
- C2 = Final concentration of the stock solution
2 x 10 = 0.5 x V2
20 = 0.5V2
\(\frac{20}{0.5}\) = V2
= 40dm\(^3\)
| Gas | CO\(_2\) | N\(_2\) |
O\(_2\) |
| % Volume | 4 | 72 | 24 |
The above table shows the compositions of the atmosphere of planet X. Which of these gases are present in higher percentages on earth?
CO\(_2\) and O\(_2\)
N\(_2\) and CO\(_2\)
CO\(_2\), O\(_2\) and N\(_2\)
O\(_2\) and N\(_2\)
The air in the Earth's atmosphere contains approximately 78% nitrogen and 21% oxygen, and a small amount of other gases such as hydrogen, carbon dioxide, and neon.
Hard water is water with high concentrations of dissolved ions, in particular, calcium and
magnesium ions
nitrogen ions
phosporus ions
helium ions
The hardness of water is determined by the amount of dissolved ions, majorly calcium and magnesium.