2021 - JAMB Chemistry Past Questions and Answers - page 3

One mole of carbon dioxide molecules has a mass 44.01g.

220/44.01 = 4.9989

Hence, 5 mole of carbon dioxide molecules.

Nitrogen (N₂) is the most abundant naturally occurring gas is Nitrogen (N2), making up about 78% of air.

Oxygen (O2), on the other hand, is the second most abundant gas making up about 21%.

Heat capacity, also known as thermal capacity, is a physical property of matter defined as the amount of heat needed to cause a unit change in temperature in a given mass of material. More.

The ideal metals are metals that are stronger reducing agents than copper but not reactive enough to react with the water that the solution consists of.

 Examples of such metals:

• Zinc
• Aluminium
• Iron

The nucleus of an atom consists of protons and neutrons.

The electron is a negatively charged subatomic particle that orbits the nucleus of an atom.

Mass of solution = Mass of solute + Mass of solvent → 20g + 180g

Hence, Mass of solution = 200g

Mass Percent = \(\frac{Mass of Solute}{Mass of Solution} * 100%\)

Mass percent = \(\frac{20}{200} * 100%\)

Mass percent = 10%

The Group 7 elements are called "halogens". They appear in the vertical column, second from the right, in the periodic table. 

Bromine(35) is among the elements in the Group.