Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.
The sulphide that is commonly used in coating electric fluorescent tubes is?
iron(ii)Sulphide
tin(ii)sulphide
Zinc Sulphide
lead(iv) Sulphide
Correct answer is C
ZnS (Zinc Sulfide) screen was used because it emits a flash of light when struck by an alpha particle.
This is a phenomenon called Radio luminescence in which a flash of light is observed on the screen when acted upon by a radioactive substance.
How many neutrons are present in atom with mass number and atomic number 37 and 17 respectively?
18
20
37
17
Correct answer is B
The mass number = number of neutrons + atomic number.
number of neutrons = The mass number - atomic number.
number of neutrons = 37 - 17 = 20
The following non-metal form acidic oxides with oxygen except?
phosphorus
sulphur
carbon
chlorine
Correct answer is C
The oxides which neither react with acids nor react with bases are known as neutral oxides.
Carbon monoxide neither reacts with acids nor reacts with bases.
Thus, carbon monoxide is a neutral oxide, produced when combustion reactions are not fully completed, either through lack of oxygen or due to low mixing
In the preparation of salts, the method employed will depend on the?
composition
dissociating ability
stability to heat
precipitating ability
Correct answer is C
The method used to prepare a salt depend on:
the solubility of the salt in water.
the heat stability of the salt