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.
Which of the following types of bonding does not involve the formation of new substances?
Metallic
Covalent
Co-ordinate
Electrovalent
Correct answer is A
Metallic bond does not involve the formation of a new substance. It is responsible for several characteristic properties of metals such as their shiny lustre, their malleability, and their conductivities for heat and electricity
A gaseous metallic chloride MCl consists of 20.22% of M by mass. The formula of the chloride is?
[ M = 27, Cl = 35.5]
MCl
MCl2
MCl3
M2Cl6
Correct answer is C
| M | Cl | |
| % composition | 20.22 | 79.78 |
| Atomic mass | 27 | 35.5 |
| Mole ratio | 20.22 | 79.78 |
| 27 | 35.5 | |
| 0.75 | 2.25 | |
| Divided | 0.75 | 0.75 |
| 1 | 3 |
The formula of the Chloride = MCl3
26.0kj/mol
65.0kj/mol
130.0kj/mol
260.0kj/mol
Correct answer is B
32g of CUSO4 liberate 13.0kj of heat
Molar mass of CUSO4 = 160g
No. of moles of CUSO4 = 32g
No. of moles = 32(mass) / 160(molar mass)
= 0.2 moles
i.e 0.2 = 13kj
1 moles = xkj
: 65KJ
Helium is used in observation of ballons because it is?
Light and combustible
light and non-combustible
heavy and combustible
heavy and non-combustible
Correct answer is B
Helium floats because it is buoyant; its molecules are lighter than the nitrogen and oxygen molecules of our atmosphere and so they rise above it