CIE Chemistry Paper-1: Specimen Questions 45 - 47 of 99
Question number: 45
An atom has electronic configuration of 2, 8, 7. Find atomic number and its group?
We have an atom with electronic configuration of 2, 8, 7.
By adding 2 + 8+7 = 17, we will get the atomic number.
Electronic configuration of the element will be 1s2 2s2 2p6 3s23p5
Adding 2 + 5 = 7
Therefore the group will be VII.
Question number: 46
The structures of three compounds are shown.
Why do these all lie in same homologous series?
They are all saturated.
They all contain an even number of carbon atoms.
They all contain the same functional group.
They are all hydrocarbons.
Homologous series is a series of compounds with the same general formula, usually varying by a single parameter—such as the length of a carbon chain. Compounds within a homologous series typically have a fixed set of functional groups that gives them similar chemical and physical properties
The name “homologous series” is also often used for any collection of compounds that have similar structures or include the same functional group.
Question number: 47
Find correct statement regarding displacement reaction?
Displacement reaction is one in which one part of a molecule is displaced by other.
Displacement reaction is one in which two or more elements combines together to form a single compound
placement reaction is the loss of electrons by a molecule
Displacement reaction is the loss of electrons by a molecule
Displacement reaction is a chemical reaction in which a more reactive element displaces a less reactive element from its compound. Both metals and non-metals take part in displacement reactions.