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 arrangements shows increasing order of reactivity of the halogens?
F2 > Cl2 > Br2 >I2
I2 < Br2 < Cl2
F2 < Cl2 < Br2
I2 > Br2 > Cl2 > F2
Correct answer is B
The reactivity of halogens decreases as you move down Group 7.
Halogens become less reactive as you move down the group as the atomic radius of the element increases which means that the distance between the outer shell of electrons and the nucleus increases.
An unsaturated solution differs from a saturated solution at a given temperature because it
Cannot dissolve more solute
Can hold more solute than it can actually dissolve
Can still dissolve more solute at given temperature
Form crystal more easily on cooling
Correct answer is C
An unsaturated solution contains a lesser amount of solute than that in a saturated solution. It can go on to dissolve more quantities of solute at the same temperature until it becomes a saturated solution.
Aluminium is used in the manufacture or aircraft because it
Is hard and brittle
Is light and resists corrosion
Has high density and conducts electricity
Is malleable and ductile
Correct answer is B
No explanation has been provided for this answer.
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 300×0.41000
= 0.12mole
Number of moles = MassMolecular mass
Mass = number of moles x m.mass
= 0.12 x 56 = 6.72g