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.
What is the oxidation number of chromium in K2CrO4?
+1
+2
+4
+6
Correct answer is D
K2CrO4 (O.N of K) X 2 + O.N of Cr + (O.N of oxygen) X 4 = 0
1 X 2 + X + -2 X 4 = 0
2 + x + -8 = 0
2 + x - 8 = 0
x = 8 - 2 = + 6
Which of these cell notations is the correct representation of a Daniell cell?
Zn(s) / Zn2+(aq) // Cu2+(aq)/Cu(s)
Cu(s) / CU2+(aq) // Zn2+(aq) / Zn(s)
Zn2+(aq) / Zn(s) // Cu2+(aq) /Cu(s)
Cu2+(aq) / Cu(s) // Zn(s) / Zn2+(aq)
Correct answer is A
No explanation has been provided for this answer.
lower the value of ∆H
increase the time for attainment of equilibrium
shorten the time for attainment of equilibrium
decrease the yield of ammonia
Correct answer is C
No explanation has been provided for this answer.
CI-
Pb 2+
SO 2-
Zn2+
Correct answer is A
No explanation has been provided for this answer.
What process is illustrated below? S(s) ⇌H2O⇌ S (aq)
Decomposition of a solid
Melting of a solid
Formation of saturated solution of a solid
Sublimation of a solid
Correct answer is C
From the given equation:
\(S_{(s)} ⇌ S_{(aq)}\) (in the presence of (\(H_2O\))
The solid form has changed to an aqueous solution upon dissolution in water. Due to the presence of the reversible reaction arrow ⇌, the solution (aqueous) formed is saturated, this is because a saturated solution is an equilibrium system