CO(g) + H\(_2\) O\(_{(g)}\) → CO\(_{2(g)}\) + H\(_{2(g)}\)
Calculate the standard heat change of the reaction above, if the standard enthalpies of formation of CO\(_{2(g)}\), H\(_2\)O\(_{(g)}\) and CO\(_{(g)}\) in kJmol\(^{-1}\) are – 394, -242 and – 110 respectively.
- A. + 262 KJ mol -1
- B. - 262 KJ mol -1
- C. + 42 KJ mol -1
- D. - 42 KJ mol -1
A metal M displaces zinc from ZnCl solution
This shows that
- A. electrons flow from zinc to M
- B. M is more electropositive than zinc
- C. M is more electonegative than zinc
- D. zinc is more electropositive than M
What number of moles of Cu 2+ will be deposited by 360 coulombs of electricity?
[f = 96500 C mol -1]
- A. 5.36 x 10 -4 mole
- B. 1. 87 x 10 10 -3 mole
- C. 9. 35 x 10 -4 mole
- D. 3. 73 x 10 -3
\(Na_2O_{2(s)} + H_2O_{(1)}\)→ \(NaOH_{(s)} +O_{2(g)}\)
The substance that is oxidized in the reaction above is
- A. \(Na_2O_{2(s)}\)
- B. NaOH(aq)
- C. H2O(1)
- D. O2(g)
A major factor considered in selecting a suitable method for preparing a simple salt is its
- A. Crystalline from
- B. melting point
- C. reactivity with dilute acids
- D. solubility in water
During a titration experiment, 0.05 moles of carbon (lV) oxide is liberated. What is the volume of gas liberated?
- A. 22.40 dm 3
- B. 11.20 dm 3
- C. 2.24 dm 3
- D. 1.12 dm 3
The number of hydroxonium ions produced by one molecule of an acid in aqueous solution is its
- A. basicity
- B. acid strength
- C. pH
- D. concentration
Which of the following will produce a solution with pH less than 7 at equivalent point?
- A. HNO 3 +NaOH
- B. H 2SO 4 + KOH
- C. HCL +Mg (OH) 2
- D. HNO 3 + KOH
Which of the following pollutants is associated with brain damage?
- A. Carbon (ll) oxide
- B. Radioactive fallout
- C. Biodegradable waste
- D. Sulphus (lV) oxide
Potassium trioxochlorate (V)has a solubility of 1.5 mol dm -3 at 45 oC.On cooling this solution to a temperature of 20 oC, the solubility was found to be 0.5 mol dm -3. What mass of KCIO 3 was crystalized out?
[K = 39, Cl = 35.5 O =16]
- A. 1.00g
- B. 10.00g
- C. 12.25g
- D. 122.50g
The solubilites of different solutes in a given solvent can be compared by
- A. plotting their solubility curves on separete axes
- B. plotting their solubility curves on the same axes
- C. plotting some of the solubility curves on the x-axis and others on the y-axis
- D. plotting their solubility curves on the x-axis only
Chlorination of water for town supply is carried out to
- A. make the water colourless
- B. remove germs from the water
- C. make the water tastedful
- D. remove odour from the water
The chemicals used to soften hard water involves the addition of
- A. insoluble sodium compounds which from soluble solutions of calcium and magesium
- B. solube soudium compounds which from soluble solutions of calcium and magnesium ions
- C. solube sodium compounds which from insoluble precipitates of calcium and magnesium ions
- D. insoluble precipitates of calcium and magnesium ions
I. It has a varied composition from one place to another. ll. it constituents can be separated by physical means
lll. It contains unreactive noble gases
which of the above shows that air is a mixture?
- A. I and ll only
- B. ll and lll only
- C. l and lll only
- D. l,lll and lll
Which of the following is used to study the arrangement of particles in crystal lattices?
- A. Alpha-particles
- B. Beta-particles
- C. Gamma-rays
- D. X-rays
Group VII elements are
- A. monoatmic
- B. good oxidizing agents
- C. highly electropositive
- D. electron donors
The electronic configuration of Mg 2+ is
- A. ls 22s 22P 63s23P2
- B. Is22s22P6
- C. ls22s22p63s2
- D. ls22s22P4
A hydrogen atom which has lost an electron contains
- A. one proton only
- B. one neutron only
- C. one proton and one neutron
- D. one proton, one electron and one neutron
If the elements X and Y have atomic numbers 11 and 17 respectively, what type of bond can they form?
- A. Dative
- B. Covalent
- C. Ionic
- D. Metallic
l . Evaporation. ll. Sublimation. lll. Diffusion. IV. Brownian motion.
Which of the above can correctly be listed as evidences for the particulate nature of matter?
- A. I and lll only
- B. ll and lV only
- C. l, ll and lll only
- D. l, ll, lll and lV