20. A solution is also called a               .
(A) homogeneous mixture
(B) heterogeneous mixture
(C) pure mixture
(D) compound
(E) distilled mixture

16. Which one of the following descriptions about CE (capillary electrophoresis) is incorrect? (A) Electrophoresis is a separation technique based on the different migration rates of charged species. (B) It cannot be used to separate proteins and nucleic acids. (C) Its particular strength is the unique ability to separate charged macromolecules. (D) Until the appearance of CE, electrophoretic separations were not carried out in columns. (E) Most of the detectors used for HPLC can be employed for CE.

17. The pH meter is widely used for measuring the H+ concentrations in the solutions. Which one of the following descriptions for a pH is incorrect? (A) The sensing material is a special thin glass membrane at the tip of the electrode. (B) No reference electrode is required for a pH meter. (C) The real signal obtained from the pH meter is voltage (or difference of potentials). (D) In basic solutions, the indicator electrode also responds to alkali metal ions. (E) pH meters can be used to determine the equivalence point of the acid-base titration.

18. Atomic spectrometer is widely applied for the analysis of various elements. Which one of the following is not an atomization method used for most atomic spectrometer? (A) Flame (B) Inductively coupled plasma (C) Electrothermal oven (D) Laser (E) Electric spark

19. A method of separation that employs a system with two phases of matter, a mobile phase and a stationary phase, is called               . (A) filtration (B) chromatography (C) distillation (D) vaporization (E) homogenization

21. Which one of the following descriptions for the Beer’s law is incorrect? (A) Beer’s law is ordinarily represented as A =εbs. (B) For a mixture, the total absorbance at a λ=the sum of individual absorbance if there is no intermolecular interaction. (C) Beer’s law is more suitable for concentrated solutions. (D) Negative deviations are always observed if polychromic radiations are used. (E) The b term in the equation of item (a) means the optical length.

22. Buffer solutions are very important for many analytical applications. Which one of the following descriptions about buffer solutions is incorrect? (A) Buffer solutions are generally from conjugate acid/base pairs. (B) Buffer solutions can resist to changes of pH when the solutions are diluted or added with strong acids or bases. (C) The buffer capacity is the measurement of ability that resists to pH changes. (D) The buffer capacity of a solution is determined by the strength of the conjugate acid/base pair. (E) The pH of a buffer solution can be determined by pH=pKa + log ([base]/[acid]).

23. Which one of the following apparatuses is not used for measurement of volume? (A) Volumetric (B) Pipet (C) Buret (D) Test tube (E) All of these are used for measurement of volume.

24. What is the major product of the following reaction?(A) (B)(C) (D) (E) None of the above

25. Which one of the following molecular formulae can represent a pair of mirror image isomers? (A) H2NCH2COOH (B) H2NCH(CH3)COOH (C) H2NCH2CH2COOH (D) H2NCH2COOCH3 (E) (CH3)2CHCOOH

26. A chain reaction is one that : (A) involves a series of steps (B) involves two steps with similar energies of activation (C) is initiated by heat (D) requires the addition of an external terminating agent (E) involves a reaction in which the propagation steps also produce the product and initiator necessary for another propagation cycle