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Chemistry WAEC / WASSCE 2017 Matter & Separation Techniques
The seperation of Nitrogen from oxygen using fractional distillation of air is possible because
A
nitrogen is less dense than oxygen
B
oxygen is more reactive than nitrogen
C
of the difference in their boiling points
D
they belong to the same period
medium Difficulty
Chemistry WAEC / WASSCE 2017 Matter & Separation Techniques
The purity of a solid sample can best be determined by its
A
boiling point
B
melting point
C
conductivity
D
solubility
medium Difficulty
Chemistry WAEC / WASSCE 2017 Stoichiometry & Mole Concept
The mass of one mole of \((NH_{4})_{2}CO_{3}\) is [O=16.0, N=14.0, C=12.0, H=1.0]
A
66.0g
B
76.0g
C
80.0g
D
96.0g
medium Difficulty
Chemistry WAEC / WASSCE 2017 Atomic Structure and Periodic Table
Atomic orbital is
A
the circular path through which electrons revolve round the nucleus
B
a region around the nucleus where electrons are most likely to be found
C
the path around the nucleus through which electrons move
D
the path around the nucleus through which protons move
medium Difficulty
Chemistry WAEC / WASSCE 2017 Atomic Structure and Periodic Table
The property of elements which increases down a group of the periodic table is
A
electronegativity
B
electron affinity
C
ionic radius
D
ionization energy
medium Difficulty
Chemistry WAEC / WASSCE 2017 Atomic Structure and Periodic Table
The reason for the decrease in the atomic size of elements across a period is that
A
nuclear charge increases while the outermost electrons are drawn closer to the nucleus
B
nuclear charge decreases while the outermost electrons are drawn closer to the nucleus
C
valence electrons increase across the period while the valence shell remains constant
D
nuclear charge decreases while the distance of the valence shell from the nucleus is increasing
medium Difficulty
Chemistry WAEC / WASSCE 2017 Electrochemistry and Redox
The oxidation number of nitrogen in \(Pb(NO_{3})_{2}\) is
A
+2
B
+3
C
+4
D
+5
medium Difficulty
Chemistry WAEC / WASSCE 2017 Matter & Separation Techniques
Which of the following arrangements indicates the correct decreasing order of ionization energy of period 3 elements?
A
Na, Al, P, Cl
B
Cl, P, Al, Na
C
Na, P, Cl, Al
D
Al, Na, P, Cl
medium Difficulty
Chemistry WAEC / WASSCE 2017 Atomic Structure and Periodic Table
Which of the following metals has the strongest metallic bond?
A
\(_{13}Al\)
B
\(_{19}K\)
C
\(_{12}Mg\)
D
\(_{11}Na\)
medium Difficulty
Chemistry WAEC / WASSCE 2017 Matter & Separation Techniques
Which of the following substances does not have van der Waals' forces?
A
Copper
B
Graphite
C
Neon
D
Iodine crystals
medium Difficulty
Chemistry WAEC / WASSCE 2017 Electrochemistry and Redox
The oxidation number of X in \(XO_{4}^{3-}\) is
A
+1
B
+3
C
+4
D
+5
medium Difficulty
Chemistry WAEC / WASSCE 2017 Atomic Structure and Periodic Table
The ionization energy is affected by the following factors except
A
distance of the outermost electron(s) from the nucleus
B
size of the positive nuclear charge
C
ability to attract shared electron(s)
D
screening effect of the inner electron(s)
medium Difficulty
Chemistry WAEC / WASSCE 2017 Atomic Structure and Periodic Table
Which of the following statements is correct?
A
Covalent compounds would readily ionize in solution
B
Covalent compounds consist of ions
C
Hydrogen bond is formed between a metal and a non-metal
D
Ionic compounds in solution would conduct electricity
medium Difficulty
Chemistry WAEC / WASSCE 2017 Atomic Structure and Periodic Table
The bond angle in tetrahedral molecules such as tetrachloromethane is
A
180.0°
B
109.5°
C
105.5°
D
90.0°
medium Difficulty
Chemistry WAEC / WASSCE 2017 Stoichiometry & Mole Concept
The properties of a good primary standard include the following except
A
high molecular mass
B
low molecular mass
C
high degree of purity
D
readily available
medium Difficulty
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