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.
N12.00
N27.00
N63.00
N95.00
Correct answer is C
For X: X\(^{2+}\) + 2e\(^-\) \(\to\) X
2F = 63g
xF = 6g
x = \(\frac{6 \times 2}{63} = \frac{4}{21} F\)
\(\frac{4}{21}\)F = N12.00
1F = \(\frac{12}{\frac{4}{21}}\)
= N63.00
1F is equivalent to N63.00.
For Y: Y\(^{3+}\) + 3e\(^-\) \(\to\) Y
3F = 27g
xF = 9g
x = \(\frac{3 \times 9}{27}\)
= 1F
1F = N63.00
N10.00
N6.00
N20.00
N9.00
Correct answer is D
X\(^{3+}\) + 3e\(^-\) \(\to\) X
3F = 27g
xF = 10g
\(\frac{x}{3} = \frac{10}{27} \implies x = \frac{10}{9} F\)
\(\frac{10}{9}\)F \(\equiv\) N20.00
1F is equivalent to x
\(\frac{1}{\frac{10}{9}} = \frac{x}{20}\)
\(\frac{9}{10} = \frac{x}{20} \implies x = N18.00\)
1F is equivalent to N18.00.
Y\(^{2+}\) + 2e\(^-\) \(\to\) Y
2F = 24g
xF = 6g
x = \(\frac{6 \times 2}{24} = \frac{1}{2} F\)
1F = N18.00
\(\frac{1}{2}\)F = \(\frac{1}{2} \times N18.00\)
= N9.00
Hydrogen diffused through a porous plug
thrice as fast as oxygen
at the same speed as oxygen
four times as fast as oxygen
twice as fast as oxygen
Correct answer is C
Using Graham's Law of Diffusion,
\(\frac{R_1}{R_2} = \sqrt{\frac{m_2}{m_1}}\)
\(\frac{R_H}{R_O} = \sqrt{\frac{m_O}{m_H}}\)
\(\frac{R_H}{R_O} = \sqrt{\frac{32}{2}}\)
\(\frac{R_H}{R_O} = \sqrt{16} = 4\)
\(\therefore R_H = 4 \times R_O\)
Therefore, hydrogen diffuses 4 times faster than oxygen.
The emission of two successive beta particles from the nucleus \(^{32} _{15} P\) will produce
\(^{30} _{14}\)Si
\(^{32} _{13}\)Al
\(^{32} _{17}\)Cl
\(^{32} _{16}\)S
Correct answer is C
\(^{32} _{15}\)P \(\to\) 2\(^{0} _{-1}\)e + \(^{a} _{b}\)X
32 = 2(0) + a
a = 32
15 = 2(-1) + b
b = 15 + 2
b = 17
\(\therefore\) \(^{a} _{b}\)X = \(^{32} _{17}\)Cl
The velocity, V of a gas is related to its mass, M by (k = proportionality constant)
V = \(\frac{k}{M}\)
V = \(\frac{k}{M^{\frac{1}{2}}}\)
V = \(kM^2\)
V = \((\frac{k}{M})^{\frac{1}{2}}\)
Correct answer is B
Recall:
V = \(\sqrt{\frac{3RT}{M}}\)
\(\therefore V \propto \frac{1}{\sqrt{M}}\)
\(V = \frac{k}{\sqrt{M}}\)
V = \(\frac{k}{M^{\frac{1}{2}}}\)