ABU Chemistry 2020/2021 Past Questions

Practice each question, then open it to see the full details.

The oxidation state of manganese in KMnO₄ is

A.+7
B.+3
C.+5
D.+1

An increase in temperature requires an increase in pressure of gas because

A.It decreases the number of collisions between the molecules
B.The molecules of the gas bombard the walls of the container more frequently
C.It increase the number of collisions between the molecules
D.It causes the molecules to combine

Indicate which of the following statements is not true as move from left to right along the periodic table

A.Atomic number of the elements increases
B.Electropositive character of elements increases
C.Atomic mass of elements increases
D.Number of electrons in the outermost orbit of elements increases

Nitrogen is very uncreative because_____

A.Much energy is needed to break the bond between the two nitrogen atoms in the molecules.
B.Less energy is needed to break the bond between the two nitrogen atoms in the molecules
C.Of the electrovalent bond between the two atoms
D.Of the covalent bond between the two atoms.

A brand of ink containing cobalt (II), copper (II) and iron can best be separated into its various components by:

A.fractional crystallization.
B.fractional distillation.
C.sublimation
D.chromatography.

Which of the following substances is a mixture?

A.Granulated sugar
B.Sea-water
C.Sodium chloride
D.Iron filings.

The atomic numbers of two elements X and Y are 12 and 9 respectively. The bond in the compound formed between the two elements is?

A.ionic
B.covalent
C.neutral
D.co-ordinated.

When two end alkyl groups of ethyl ethanoate are interchanged, the compound formed is known as

A.methyl ethanoate
B.ethyl propanoate
C.methyl propanoate
D.propyl ethanoate

Phosphorus is stored under water to prevent it from

A.dehydrating
B.becoming inert
C.smelling
D.catching fire

The chemical used for coagulating in water purification is

A.aluminium tetraoxosulphate (IV)
B.copper tetraoxosulphate (VI)
C.sodium tetraoxosulphate (IV)
D.calcium tetraoxosulphate (IV)