CO(g) + H2O(g) → CO2(g) + H2(g)
From the reaction above, calculate the standard enthalpies of formation if CO2(g), H2O(g) and CO(g) in kJ mol-1 are -394, -242, and -110 respectively.
- A. -262 kJ mol-1
- B. -42 kJ mol-1
- C. +42 kJ mol-1
- D. +262 kJ mol-1
In the electrolysis of a concentrated solution of sodium chloride using electrodes, which of the following ions are discharged at the cathode and anode respectively?
- A. Na+ and Cl-
- B. Na+ and OH-
- C. H+ and OH-
- D. H+ and Cl-
When at equilibrium, which of the reactions below will shift to the right if the pressure is increased and the temperature is kept constant?
- A. 2SO3(g) ↔ 2SO2(g) + O2(g)
- B. 2CO2(g) ↔ 2CO(g) + O2(g)
- C. 2H2(g) + O2(g) ↔ 2H2O(g)
- D. 2NO(g) ↔ N2(g) + O2(g)
If y is an oxidizing agent that reacts with a reducing agent, Z, which of the following is correct?
- A. Y increases in oxidation number
- B. Y becomes reduced
- C. Z loses protons
- D. Z gains protons
Which of the following will change when a catalyst is added to a chemical reaction?
- A. The activation energy
- B. The potential energy of the reactants
- C. The heat of the reaction
- D. the potential energy of the product
The commonest feature of reactions at the anode is that
- A. electrons are consumed
- B. oxidation is involved
- C. ions are reduced
- D. electrode dissolves
If an equilibrium reaction has ΔH > 0, the reaction will proceed favourably in the forward direction at
- A. High temperature
- B. Any temperature
- C. Low temperature
- D. Minimum temperature
A change in temperature of a saturated solution disturb the equilibrium between the
- A. Dissolved solute and the solvent
- B. Solvent and undissolved solute
- C. Dissolved solute and undissolved solute
- D. Dissolved solute and the solution
When 10g of sodium hydroxide is dissolved in 1000cm\(^3\) of water, the sodium formed is approximately
[Na = 23, H = 1, O = 16]
- A. 0.01 mol dm-3
- B. 0.10 mol dm-3
- C. 0.25 mol dm-3
- D. 0.50 mol dm-3
Farmlands affected by crude-oil spillage can be decontaminated by
- A. Adding acidic solution
- B. Using aerobic bacteria
- C. Pouring water on the affected water area
- D. Burning off the oil from the area
What mass of K2CrO4 is required to prepare 250cm3 of 0.020 mol dm3 solution?
[K2CrO4 = 194.2g mol-1]
- A. 0.97g
- B. 9.70g
- C. 19.42g
- D. 97.10g
A liquid that will dissolve fat is?
- A. Hydrochloric acid
- B. Calcium hydroxide
- C. Kerosene
- D. Water
The structural component that makes detergent dissolve more quickly in water than soap is
- A. -SO3- Na+
- B. -COO-Na-
- C. -SO4- Na+
- D. -COO-K+
Which of the following ions is acidic?
- A. K+
- B. KNO3-
- C. S2-
- D. H3O+
A consequence of global warming is?
- A. air pollution
- B. water pollution
- C. increased humudity
- D. flooding
The weakest attractive force that can be observed between two molecules is
- A. ionic
- B. covalent
- C. coordinate covalent
- D. van der Waals
When cathode rays are deflected onto the electrode of an electrometer, the instrument becomes
- A. negatively charged
- B. positvely charged
- C. neutral
- D. bipolar
A gas exerts pressure on its container because
- A. some of its molecules are moving faster than others
- B. of the collision of the molecules with each other
- C. of the mass of the molecules of gas
- D. the molecules of a gas colide with the walls of the container
I. H = 1S\(^1\) II. N = 1S\(^2\) 2S\(^2\)2P\(^3\) III. O = 1S\(^2\) 2S\(^2\) 2P\(^4\) IV. Zn = 1S\(^2\) 2S\(^2\) 2P\(^6\) 3S\(^2\) 3P\(^6\) 4S\(^2\) 3d\(^{10}\)
From the above, which of the following pairs is like to be paramagnetic?
- A. I and II
- B. I and III
- C. I and IV
- D. III and IV
According to the kinetic theory, an increase in temperature causes the kinetic energy of particles to
- A. Decrease
- B. Increase
- C. Remain constant
- D. Be zero
The noble gases owe their inactivity to
- A. Octet configuration
- B. Cyclic shape
- C. Hexagonal shape
- D. Obtuse configuration