UNICAL Chemistry 2019/2020 Past Questions

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

The main characteristics feature of transition metals are that they

A.forms ions easily
B.are reducing agents
C.have the same atomic size
D.have variable oxidation states

If an element has the electronic configuration $$1s^2 2s^2 2p^6 3s^2 3p^4$$, it is

A.metal
B.an alkaline earth metal
C.an s-block element
D.a p-block element

An oxide XO₂ has a vapour density of 32. What is the atomic mass of X?

A.32
B.20
C.14
D.12

Aluminium is a good roofing material because it

A.is strong and does not conduct heat and electricity
B.readily absorbs light
C.forms an oxide film over its surface which prevents corrosion
D.is flexible and can conduct heat

An atom can turn into an ion if it

A.gains a proton
B.loses a proton
C.gains a neutron
D.loses an electron

Commercial bleaching can be carried out using

A.sulphur(IV) oxide and ammonia
B.hydrogen sulphide and chlorine
C.chlorine and sulphur(IV) oxide
D.ammonia and chlorine

25cm³ of a mixture of noble gases was obtained from air after the removal of other constituents. What was the original volume of air?

A.2500cm³
B.1250cm³
C.125cm³
D.80cm³

In any chemical reaction, the total mass of the products is always equal to that of the reactants. This is statement of the law of

A.definite proportions
B.conservation of matter
C.multiple proportions
D.constant composition

P_(g) + G_(g) <--->3R_(s) + S_(g), ∆H is negative. Which of the following will increase the yield of R?

A.Using a larger closed vessel
B.Increasing the temperature
C.Removing some S
D.Adding a positive catalyst.

Which of the followthg ions is acidic?

A.K⁺
B.NO₃^-
C.S^2-
D.H₂O⁺