Review Material for Ncae

REVIEW MATERIAL FOR NCAE Chemistry A.Y. 2010-2011 1. Greg prepares a solution by adding some green crystals to water in a beaker, then stirring while the crystals dissolve. Consider the following observations: A. The water becomes green. B. Crystals disappear from the bottom of the beaker. C. The beaker and its contents become heavier as stirring continues. C. The color of the solution becomes darker. Which of those listed above are likely to be observed by the student? a. A and B only c. A, B, and D only b. C and D only d. A, B, C, and D 2. Which property of a pure substance is similar to that of a solution? a. constant boiling point c. fixed composition b. sharp melting point d. Homogeniety 3. Which is an extrinsic property? a. density c. boiling point b. weight d. color 4. Which of the following turns blue litmus paper to red? a. soap solution c. distilled water b. vinegar d. ethyl alcohol 5. What state of matter is inside the sun and the stars? a. solid c. gas b. liquid d. plasma 6. Which statement about colloids is true? a. Colloids contain particles bigger than those is solution and suspension. b. Colloids contain particles that do not settle due to Brownian movement. c. A ray of light is not deflected when it hits a colloid due to its small size. d. None of the Above 7. Which mixture is best separated by simple distillation? a. Mixture of two insoluble liquids. b. Mixture of a liquid and a soluble liquid. c. Mixture of a liquid and an insoluble solid. d. Mixture of two soluble liquids. 8. Which of the following statements about isotopes of hydrogen is correct? a. They have the same number of protons. b. They have the same number of neutrons. c. They have different numbers of electrons. d. they have different atomic number. 9. Which of the following best describes a neutron? a. It has a negative charge. b. Its mass is much greater than the proton. c. It is found in the nucleus. d. the number of neutrons is called the mass number.

10. An element with an atomic number of 15 ha the electron configuration. a. [ Ne]3s23p3 c. [ Ne]2d5 2 3 b. [ Ne]3s 3d d. [ Ne]3s23f3 11. Which of the following has the smallest value of the first ionization energy? a. 37Rb c. 7N b. 29Cu d. 55Cs For questions 12 to 15, refer to the following electron configurations of neutral atoms. J : 1s1 K : 1s2s21 L : 1s22s22p3 M : 1s2 N : 1s22s2sp5 12. A covalent bond would be expected to form between elements a. L and N c. J and K b. K and N d. J and N 13. What pair of elements would likely form an ionic bond? a. L and N c. J and M b. K and N d. J and J 14. If L and N were to form a compound, what would be the resulting formula? a. LN2 c. L2N b. LN d. LN3 15. A balanced chemical equation demonstrates the law of a. Conservation of Mass c. Multiple Proportion b. Conservation of Energy d. Definite Proportion 16. During chemical reaction, the reactants are changed to its products due to the rearrangement of a. protons c. innermost electron b. neutrons d. outermost electron 17. Boyle’s law states that the pressure of a gas is inversely proportional to its a. mass c. temperature b. volume d. density 18. At constant pressure, the temperature of a gas is directly proportional to its a. molar mass c. number of molecule b. volume d. density 19. If the air inside a balloon is heated, the volume will a. decreases c. increase slightly then decrease b. increase d. remain the same 20. If a gas volume is doubled but the temperature remains constant a. the molecules move faster c. the molecules move slower b. the pressure stays the same d. None of the Above 21. The fact that a balloon filled with He will deflate more slowly than one filled with H2 can be explained by a. Dalton’s Law c. Graham’s law b. Avogadro’s law d. Boyle’s law 22. A solution in which the rates of dissolving and crystallizing are equal is a. diluted c. saturated b. unsaturated d. supersaturated

23. An aqueous solution contains 64.0 g of ethanol (C2H5OH) in 122.0 g solution. What is the mole fraction of ethanol in the solution? a. 0.205 c. 0.302 b. 0.432 d. 0.70 24. Sodium chloride is dissolved in water as given in the choices. Which solution is the most concentrated? a. 20 g salt dissolved in 25 ml of H2O c. 6 g salt dissolved in 5 g of H2O b. 15 g salt dissolved in 18 ml of H2O d. 10 g of salt dissolved in 20 g of H2O 25. Which of the following would decrease the rate in which a solid dissolves in a liquid? a. increasing the temperature of an exothermic reaction b. grinding the solid into smaller pieces c. applying pressure into the solution d. supersaturating the solution 26. In order for a chemical reaction to occur, there must always be a. an effective collision between reacting particles b. a bond that breaks in a reactant particle c. a bond that forms in a product particles d. reacting particle with high energy 27. Which change would most likely increase the rate of a chemical reaction? a. cooling the reaction mixture b. decreasing the concentration of the reactants c. decreasing the surface area of the reactant d. adding a catalyst to the reaction mixture 28. Which of the following statements on specific heat is true? a. It is an extrinsic property. b. it is the heat capacity per mole of a substance. c. It is equal to zero when the heat capacity is zero. d. it is always equal to the heat capacity. 29. Which of the following is an example of Chemical Change? a. breaking of glass b. decay of plants b. formation of clouds d. expansion of a balloon 30. Which of the following is an example of intrinsic property? a. mass c. size b. boiling point d. thickness 31. How many significant numbers are in 6.35 cm? a. 3 b. 2 c. 0 d. 1 32. Isotopes have the same number of ____________________. a. protons and neutrons c. electron and neutron b. protons and neutrons d. electron and nucleons 33. Which is not a compound? a. air c. table sugar b. table salt d. muriatic acid 34. Coffee is an example of a/an _______________. a. compound b. homogeneous c. element d. heterogeneous

35. What is the smallest particle of matter? a. element b. solution c. atom d. compound 36. Which of the following is a homogeneous mixture? a. sugar mixed with water c. sandwich b. pizza pie d. sand & gravel 37. Which is not a true about metals? a. metallic luster b. electrical ductility c. ductile d. insulators 38. It can be decomposed or broken into their constituent elements by chemical means is called ___________. a. compounds b. metals c. elements d. nonmetals 39. Which is an example of colloids? a. mud in water b. glue c. starch in water d. syrup 40. Which of the following is not a characteristic of a solid? a. has definite shape c. has the highest density b. has definite volume d. has definite shape but no definite volume