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.
Metals can be stretched into wires because they are
Ductile
Good conductors
Lustrous
Malleable
Correct answer is A
No explanation has been provided for this answer.
The mass of potassium hydroxide required to make 300.ocm3 of 0.4 moldm-3 solution is {KOH = 56.0}
26.88g
13.44g
6.72g
3.36g
Correct answer is C
300cm3 of 0.4moldm3
1000cm3 contains 0.4mole
300cm3 will contain \(\frac{300 \times 0.4}{1000}\)
= 0.12mole
Number of moles = \(\frac{Mass}{\text {Molecular mass}}\)
Mass = number of moles x m.mass
= 0.12 x 56 = 6.72g
Chemicals that are produced in small quantities and with very degree of purity are
Bulk chemicals
Fine chemicals
Heavy chemicals
Light chemicals
Correct answer is B
No explanation has been provided for this answer.
The boiling points of HF, H2O and NH3 increase in the order of
NH3
H2O < HF
HF < NH3 < H2O
NH3 < HF < H2O
Correct answer is D
Ammonia = -33.34°C; Hydrogen fluoride = 19.5°C; Water = 100°C
When element \(_{20}\)Y combines with element \(_8\)Z, it forms
A covalent compound , YZ is formed
A covalent compound, ZY is formed
An ionic compound, YZ is formed
An ionic compound, ZY is formed
Correct answer is C
Y = 2,8,8,2 and Z = 2,6.
Y will readily give off its 2 valence electrons and Z will accept the 2 electrons in order to achieve octet configuration. Hence, the compound YZ is formed by ionic bonding.