MnO4(aq) + 8H + 5Fe2+ \(\to\) Mn2+(aq) + 5Fe3+(aq) + H2O. The oxidation number of maganese in the above reaction changed from
- A. +7 to +2
- B. +6 to +2
- C. +5 to +2
- D. +4 to +2
If the relative atomic mass of an element is not a whole number, it can be deduced that the element is?
- A. Naturally radioactive
- B. abundant in nature
- C. a transition metal
- D. an isotopic mixture
The principle of column chromatography is based on the ability of the constituents to
- A. move at different speeds in the column
- B. dissolve in each other in the column
- C. react with the solvent in the column
- D. react with each other in the column
2SO2(g) + O2(g) \( \iff \)2SO3(g)
\( \bigtriangleup H = -395.7kJmol^{-1} \)
In the reaction above, the concentration of 2SO3(g) can be in creased by
- A. decreasing the pressure
- B. decreasing the temperature
- C. the addition of catalyst
- D. increasing the temperature
Zn(s) + CuSO4(aq) \( \to \) ZnSO4(aq) + Cu(s)
In the reaction above, the oxidizing agent is
- A. CuSO4(aq)
- B. ZnSO4(aq)
- C. Cu(s)
- D. Zn(s)
The radioactive emission with the least ionization power is
- A. \( \alpha - particles \)
- B. X-rays
- C. \( \gamma -rays \)
- D. \( \beta - rays \)
How many unpaired electron are in the p-orbitals of a fluorine atom?
- A. 3
- B. \( 0 \)
- C. 1
- D. 2
The following equations represent redox reactions EXCEPT
- A. Ba2+(aq) + SO2-4 (aq) → BaSO4(s)
- B. Cl2(g) + 2Br- (aq) → 2CI - (aq) + Br2(g)
- C. Fe2+(aq) + ½ C I2(aq) → Fe3+ (aq) + CI-(aq)
- D. 2Fe3+(aq) + Sn2+(aq) → 2Fe2+(aq) Sn4+ (aq)
- E. Zn(s) + CU2+(aq) → Zn2+(aq) + CU(s)
What volume of carbon (IV) oxide in dm 3 is produced at s.t.p. when 2.50g of CaCO3 reacts with excess acid according to the following equation? CaCO3(s) + 2HCI(aq) → CaCl2(aq) + H2O(1) + CO2(g)
[CaCO2 100; molar volume of a gas at s.t.p. = 22.4dm 3]
- A. 0.28
- B. 0.56
- C. 2.24
- D. 5.6
- E. 11.2
Brain tumors can be located by using an isotope of
- A. carbon - 14
- B. iodine 131
- C. technetium 99
- D. uranium235
- E. uranium 238
During the extraction of iron in the blast furnance, slag is produced using
- A. carbon
- B. crylite
- C. limestone
- D. oxygen
- E. sulphur
X = – log10 H+]
What does X stand for in the expression above?
- A. Degree of acidity
- B. Enthalpy change
- C. Equilibrium constant
- D. Ionic product of water
- E. Solubility product
Which of the following gases is absorbed from the air due to photosynthesis?
- A. Carbon (II) oxide
- B. Carbon (IV) oxide
- C. Nitrogen
- D. Noble gases
- E. Oxygen
How many atoms of chlorine are required to saturate the double bonds of a compound containing a triene?
- A. 2
- B. 3
- C. 4
- D. 5
- E. 6
All the following belong to the same family EXCEPT
- A. glycerol
- B. nylon
- C. perspex polyethene
- D. polyethene
- E. polystyrene
Ptotal = P1 + P2 + P3 +…………. Pn, is an expression of law
- A. Boyle’s
- B. Charles’
- C. Dalton’s
- D. Graham’s
- E. Gay Lussac’s
The following are ores of metals EXCEPT
- A. bauxite
- B. dolomite
- C. graphite
- D. haematite
- E. magnetite
The green house effect is a climatic condition associated with the presence of excess
- A. carbon (II) oxide
- B. carbon (IV) oxide
- C. hydrogen sulphide
- D. nitrogen (II) oxide
- E. oxygen
Which of the following is a solid at room temperature?
- A. Argon
- B. Bromine
- C. Chlorine
- D. Fluorine
- E. Iodine
The relationship between equilibrium constant and free energy change is represented as
- A. δ G ° =-nFE °
- B. δG °-RT ln K
- C. δ G °= + RT In k
- D. δG ° = δH – T S
- E. H=TδS
Which of the following salt solutions will have a pH greater than 7?
- A. NaCl
- B. NaHSO4
- C. Na2CO4
- D. Na2SO4
- E. MgCl2