CHEMISTRY 2023 WAEC CORRECT ANSWERS

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(1a)
Transition element can be defined as an element in which at least one of its simple ions or atoms has an incomplete inner shell of d-electrons. They are known as d-block elements. They are in three rows with ten elements in each row

(1b)
i – B
ii – C

(1c)
There is an increase in the first ionization energy accross the periodic table due to increase in the number of volume electrons leading to an increase in the screening effect and nuclear attraction between the nucleus and the outermost electrons.

(1d)
– Alkane eg Butane
– Alkene eg Ethene

(1e)
Alkanols are stronger base than water due to the presence of hydroxyl ions (OH-) in them.

(1f)
– Salt (Nacl)
– Limestone (CaCO3)
– Ammonia (NH3)
– Coke (C)

(1g)
This is also known as Cis-trans isomerism. It is a term which involves the spatial arrangement of atoms within the molecules

(1h)
This is because it has a high calorific value due to the combustible nature of the component gases

(1i)
Heat of combustion can be define as the amount of heat involved when 1 mole of substance burns in air or oxygen under standard conditions

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