What is the oxidation number of nitrogen in Al(NO\(_3\))\(_3\)?
- A. + 1
- B. + 3
- C. + 5
- D. + 6
A reaction is represented by the equation below. A2(g) + B2(g) → 2AB(g); ∆H = +X kJmol-1 Which of the following statements about the system is correct?
- A. The reaction goes to completion at equilibrium
- B. The forward reaction is exothermic
- C. At equilibrium increase in temperature favours the reverse reaction
- D. Pressure has no effect on the equilibrium mixture
Consider the following equation: Ag+ (aq) + CI-(aq) → Ag+CI- (s) ; ∆H = – 65.7 kJmol-1. From the equation, it can be deduced that
- A. direct combination is involved and the reaction is endothermic
- B. a solid is formed and heat is evolved
- C. activation energy is high and a catalyst is required
- D. the reaction is endothermic and occurs at high temperature
What does ∆H represent in the following equation ? Cl(g) + e- → CI- (g); ∆H = – 363 kJ mol-1
- A. lonization energy
- B. Electron affinity
- C. Dissociation energy
- D. Heat of atomization
It can be concluded that gastric juice
- A. contains enzymes
- B. is acidic
- C. is a mixture
- D. has pH value of 7
A gas was evolved when a sample of gastric juice reacted with sodium trioxocarbonate (IV) . The gas evolved was
- A. NH3
- B. SO2
- C. HCI
- D. CO2
In which of the reactions represented by the following equations is HNO3 behaving as a typical acid?
- A. CaO + 2HNO3 → Ca(NO3) 2 + H 2O
- B. Cu + 4HNO3 → Cu(NO 3)2 + 2H2O + 2NO2
- C. S + 6HNO3 → H2SO 4 + 6NO2 + 2H2O
- D. P + 5HNO3 → H 3PO 4 + 5NO2 + H2O
Which of the following would dissolve in warm dilute H2SO4 without effervescence, to give a blue solution?
- A. Copper turnings
- B. Copper (ll) trioxocarbonate (IV)
- C. Copper (ll) oxide
- D. Copper alloy
A mixture of calcium chloride and calcium trioxocarbonate (IV) in water can be separated by
- A. evaporation
- B. sublimation
- C. distillation
- D. filtration
Which of the following pairs of reagents react to produce hydrogen?
- A. Zinc and concentrated trioxonitrate (V) acid
- B. Water and calcium dicarbide
- C. Copper and dilute hydrochloric acid
- D. Magnesium and dilute tetraoxosulphate (VI) acid
P\(_{TOTAL}\) = P\(_1\) + P\(_2\) + P\(_3\) + …Pn’ where P Total is the pressure of a mixture of gasses. The equation above is an expression of
- A. Graham's law
- B. Gay-Lussac's Law
- C. Boyle's law
- D. Dalton's law
Which of the following statements about ideal gases is/are correct? 1. The cohesive forces between their particles are negligible ll. They have no definite volume but occupy the volume of their containers III. They are not compressible IV. Their particles collide with loss of energy
- A. l only
- B. l and ll only
- C. l, ll and lll only
- D. l, ll, lll, and IV
Which of the following features of a human skeleton can be determined by carbon-dating?
- A. Height
- B. Mass
- C. Age
- D. Race
A sheet of paper is placed in the path of a beam from a radioactive source. The emissions that pass through the paper consist of
- A. alpha particles and gamma rays
- B. alpha and beta particles
- C. beta particles and gamma rays
- D. alpha particles only
Which of the following compounds is covalent?
- A. CaCI2
- B. MgO
- C. NaN
- D. CH4
What is responsible for metallic bonding?
- A. Sharing of electrons between the metal atoms
- B. Attraction between the atomic unclei and cloud of electrons
- C. transfer of electrons from one atom to another
- D. Attraction between positive and negative ions
The presence of unpaired electrons in an atom of a transition metal gives rise to
- A. paramagnetism
- B. malleability
- C. malleability
- D. ductility
- E. shiny appearance
The atom of an element X combines with aluminium (\(^{13}\)AI)?
- A. AIX 2
- B. AI 2X
- C. AI2X 2
- D. AI 2X 3
Elements which belong to the same group in the Periodic Table are characterized by
- A. difference of +1 in the oxidation numbers of successive members
- B. presence of the same number of outermost electrons in the respective atoms
- C. difference of 14 atomic mass units between successive members
- D. presence of the same number of electron shells in the respective atoms