Chemistry Past Questions And Answers
A sample of any of the following substances disappears after some time when exposed to air like camphor, naphthalene, or dry ice. This phenomenon is called?
- A. Sublimation
- B. Evaporation
- C. Diffusion
- D. Radiation
H3O+(aq) + OH-(aq) → 2H2O(l). The heat change accompanying the process represented by the equation above is the heat of
- A. neutralization
- B. formation
- C. solution
- D. dilution
In 1898, which scientist proposed that the atom is a sphere of positively charged matter in which negatively charged electrons are embedded
- A) Earnest Rutherford
- B) Max Planck
- C) J.J Thomson
- D) Robert Millikan
When sugar is dissolved in tea, the reaction is always accomplished by
- A. positive change
- B. negative entropy change
- C. no entropy change
- D. a minimum entropy change
Which of the following are water pollutants?
- A. Fertilizers
- B.Human wastes
- C. Industrial wastes
- D. All of the above
X(g) + 3Y(g) ---- 2z(g) H = +ve. if the reaction above takes place at room temperature, the G will be
- A) negative
- B) zero
- C) positive
- D) indeterminate
What is the IUPAC name of the compound represented by the molecular formula NaCIO4?
- A. Sodium tetraoxochlorate (l)
- B. Sodium tetraoxochlorate (IV)
- C. Sodium tetraoxochlorate (VI)
- D. Sodium tetraoxochlorate(VII)
The reaction, A+ B \(\rightarrow\) C, can be represented by the equation, r=k[A][B], k in this equation is,
- A) proportionality constant
- B) rate constant
- C) equilibrium constant
- D) Boltzmann constant
C(s) + 2S(g) → CS2(g) ΔH = +89 kJ mol-1 The chemical equation above implies that
- A. each of carbon and sulphur has 89 kJ of energy
- B. both carbon and sulphur contribute 89 kJ of energy
- C. 89 kJ of energy is released
- D. 89 kJ of energy is absorbed
Which of the following is the difference between an electrolytic cell X and electrochemical cell Y?
- A) Anode in X is -ve while anode in Y is +ve
- B) In X, oxidation takes place at the anode while in Y reduction takes place at the anode.
- C) In X, anode is positive while in Y anode is negative
- D) In X, chemical energy is converted into electrical energy while in Y electrical energy is converted into chemical energy.