Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.
| GAS | CO2 | N2 |
O2 |
| % BY 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?
CO2 and O2
N2 and CO2
CO2, O2 and N2
O2 and N2
Correct answer is D
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.
30
40
20
50
Correct answer is B
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
200.5 = V2
= 40dm3
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
Correct answer is D
Isomers of Butene: are But-1-ene, But-2-ene, 2-Methylpropene or 2-methylprop-1-ene
How many bonding pair are present in carbon(iv)oxide?
4
3
2
1
Correct answer is A
There are 4 bond pairs in CO₂ and no lone pairs are there.