1 st Semester Exam in High School Chemistry Examination in January of 2012.

1st Semester Exam in High School Chemistry

Examination in January of 2012

1. Substance A is a liquid, Substance B is a gas and Substance C is a solid.

All of the substances are at the same temperature and pressure. Which of the following shows the correct relationship between the strength of the intermolecular forces in each substance?

A. A > B > CB. B > A > CC. C > B > AD. C > A > B

2. A balloon is inflated with room temperature air, and is placed outside in the sun. The balloon expands due to the rise in temperature. Which of the following describes what happens to the molecules of air as the temperature rises?

A. The molecules of air stop colliding with the balloon wall.

B. The molecules of air increase in size.C. There are fewer interactions between the air

molecules.D. The molecules of air move more quickly.

3. Condensation occurs when _____________________ .

A. a gas loses energy to become a liquidB. a solid gains energy to become a liquidC. a liquid gains energy to become a gasD. a gas loses energy to become a solid

4. As liquid carbon dioxide freezes, its molecules ________________ .

A. absorb heat energy and move farther apartB. absorb heat energy and move closer togetherC. release heat energy and move farther apartD. release heat energy and move closer together

5. Compared to the particles in a gas, the particles in a solid move_____________ .

A. at the same speed as the gasB. quicker and farther than the gasC. quicker than the gasD. slower than the gas

6. Which one of the following is a TRUE statement?

A. Gas molecules move around freely.B. Liquids do not change shape easily.C. Gas molecules move more slowly as they are

heated.D. Solids change shape easily.

7. Which of the following BEST describes what happens when most substances change from a solid state to a liquid state?

A. The molecules slow down.B. The molecules move farther apart.C. The molecules get smaller.D. The molecules lose energy.

8. Unlike most substances, water is unusual because it ____ when it goes from the liquid to solid state.

A. contractsB. meltsC. expandsD. diffuses

9. Which of the following is an example of a chemical change?

A. filling a balloon with heliumB. freezing a glass of waterC. a plant collecting energy from the sun to

create foodD. a dog ripping a newspaper

10. What happens to the atoms of the reactants in a chemical reaction?

A. They change into new atoms.B. They recombine to form the products.C. They change names.D. Some are lost to the environment.

11. When two substances react chemically, what type of products will be formed?

A. Products will be very similar to the reactants.B. Products will be very different from the reactants.C. The products will vary from one reaction to another.D. Products of a chemical reaction cannot be predicted.

12. A good hypothesis _____________ .

A. can be tested by experimentB. can be an educated guess predicting the

outcome of an experimentC. can only be formed when you know

something about what is going to happenD. may be described by all of the above

13. In the late nineteenth century, Dmitri Mendeleev spent two years developing a table that could be used to predict which of the following?

A. age of mineral samplesB. movements of planetsC. composition of starsD. properties of elements

14. Is science limited only to ideas and concepts that are testable?

A. Yes, because scientists can only make theories about things that have been measured.

B. Yes, because scientists cannot create new theories from nothing.

C. No, because natural phenomena can be observed, but not always measured.

D. No, because scientific theories change as public opinion changes.

15. Which family correctly labels the elements in Group 1 on the Periodic Table?

A. transition metalsB. alkali seriesC. lanthanide elementsD. actinide series

16. Which is the BEST conclusion that can be made from the information shown on the graph below?

A. Electrons in Period 3 are more difficult to remove from an atom than electrons in Period 2.

B. In general, going from left to right across a period on the Periodic Table, electrons become increasingly difficult to remove from an atom.

C. Period 2 atoms are larger in size than Period 3 atoms, decreasing the attraction of the valence electrons for the nucleus.

D. As the number of valence electrons increases, the electron removal energy decreases.

17. Melting Point of ElementsUse the data shown below to create a graph on

the element’s melting point.Element

Melting Point (oC)

Lithium 186Beryllium 1290Boron 2200Carbon 3500Nitrogen - 210.5Oxygen -218.4Fluorine -223Neon -253Potassium 63Magnesium 649Aluminum 659Silicon 1434Phosphorus 44Sulfur 112.8Chlorine -102Argon -190

Students should make a bar graph of the data.

18. Explain how the melting point of a metal compares to the melting point of a nonmetal.

18. The melting point of a metal is generally higher, except for the nonmetal that is next to the metalloid.

19. Why is an atom considered electrically neutral?

A. neutrons equal the number of protonsB. proton forces pull on the neutronsC. electrons equal the number of protonsD. electrons equal the number of neutrons

20. Which of the following statements describes isotopes of an atom?

A. different chemical propertiesB. different numbers of protonsC. different massesD. different numbers of electrons

21. Using the Periodic Table, predict which elements will have similar chemical properties or reactivity.

A. cadmium, calcium and carbonB. magnesium, strontium and bariumC. rubidium, yttrium and zirconiumD. nitrogen, sulfur and bromine

22. Choose the correct Lewis Dot diagram for NaCl.

A.

B.

C.

D.

23. As the atomic number increases, within a group of elements, the atomic radius usually ________________ .

A. decreasesB. remains the same as the one above itC. increasesD. decreases, then increases

24.Which of the following increases as the electronegativity difference between 2 atoms increases?

A. ionic nature of the bond B. covalent nature of the bondC. metallic nature of the bondD. electron sharing between the 2 atoms

25.What is the formula for potassium fluoride?

A. KFB. KF2

C. K2F

D. K2F2

26. What is the formula for the compound formed by iron (II) ions and chromate ions?

A. FeCrO4

B. Fe2CrO4

C. Fe2(CrO4)3

D. Fe(CrO4)2

27. What is the formula for aluminum hydroxide?

A. AlOHB. Al(OH)3

C. A l2(OH)3

D. A l3OH

28. What is the name of the compound: N2O3?

A. sodium dioxideB. dinitrogen oxideC. nitrous oxideD. dinitrogen trioxide

29. What is the formula for tin (IV) oxide?

A. Tn4O2

B. SnOC. TnO2

D. SnO2

30. What is the formula for barium nitrate?

A. Ba(NO3)2

B. BaNO2

C. Ba2NO3

D. Ba(NO4)2

31. What is the name of the compound AlPO4?

A. aluminum phosphideB. aluminum phosphateC. aluminum phosphiteD. aluminum phosphoroxide

32. Which of the following is the metallic ion in scandium (II) chloride?

A. Sd 2 +

B. Cl 2-

C. Sc 2 + D. Cl 1-

33. Using the Nutrition Facts label to the right, which of the following formulas is CORRECT for the highlighted ingredient?

A. Na2PO3

B. Na3PO4

C. NaPOD. Na3(PO4)2

34. Select the correct name for this compound. A l2(SO4)3

A. dialuminum trisulfateB. aluminum trisulfideC. aluminum sulfateD. sulfuric aluminate

35. Choose the correct name for the following. HClO3

A. hydrogen chloroxideB. hydrogen trichlorC. hypochloriteD. chloric acid

36. What is the name of the compound NiSO4 ?

A. nickel (II) sulfiteB. nickel (II) sulfideC. nickel (II) sulfate

37. What is the oxidation number of nitrogen in most compounds?

A. -3B. -2C. -1D. + 1

38. What is the oxidation number of hydrogen in HCl?

A. 0B. +1C. + 2D. + 3

39. Name the compound. H2O

A. dihydrogen monoxideB. hydrogen oxideC. hydrogen oxalate D. hydrogen dioxide

40. Name the following. Li2S

A. dilithium monosulfideB. lithium sulfideC. lithium disulfideD. sulfuric lithate

41. Which of the following is a possible compound formed from Calcium (2+) and the polyatomic ion Nitrate, NO3 (-1)?

A. Ca2NO3

B. Ca3NO2

C. CaNOD. Ca(NO3)2

42. Carbon tetrachloride is a solvent which is used as a refrigerant and also as a cleaning agent. Prior to the 1950s, carbon tetrachloride was manufactured by the chlorination of carbon disulfide: CS2 + 3 Cl2 → CCl4 + S2Cl2 but now it is mainly produced from methane: CH4 + 4 Cl2 → CCl4 + 4 HCl How many grams of carbon tetrachloride can be produced from reacting 709.0 grams of Chlorine (Cl2) with excess methane?

A. 3.845 gB. 61.53 gC. 384.5 gD. 6153 g

43. What is the coefficient for potassium in the balanced equation?____ Na + ____K2S → ____ K + ____ Na2S

A. 2B. 4C. 6D. 8

44. For the reaction HCl + NaOH > NaCl + H2O, which reactant is the limiting reactant given 100.0 g of sodium hydroxide and 100.0 g of hydrochloric acid?

A. hydrochloric acidB. sodium hydroxideC. sodium chlorideD. water

45. In the reaction A + B → C + D, if element B is in excess, then —

A. A is the limiting reactant.B. B is the limiting reactant.C. C is the limiting reactant.D. both A and B are limiting reactants.

46.In the reaction 2RbNO3 → 2RbNO2 + O2 how many moles of O2 are produced when 5.0 mol of RbNO3 decompose?

A. 1.0 molB. 2.5 molC. 3.0 molD. 7.5 mol

47. How many molecules are represented by 3.00 moles of oxygen, O2?

A. 4.98 x 1024

B. 3.00C. 6.32 x 102 1

D. 1.81 x 1

48. White phosphorous is used as an incendiary weapon and smoke tracer. It can also be used to create smoke screens to mask troop movement or hide platoon position. Robert Boyle was the first to use phosphorus to ignite sulfur tipped wooden splints, forerunners of our modern matches, in 1680. One of the ways in which it can be made involves the fusion of calcium phosphate with carbon and sand in an electric furnace.2Ca3(PO4)2 + 6SiO2 + 10C → 6CaSiO3 + P4 + 10CO

Starting with 100.0 grams of calcium phosphate and assuming excess silicon dioxide and carbon, how many moles of phosphorous will be produced?

A. 0.1612 molesB. 0.3224 molesC. 15510 molesD. 1.551 moles

49. Calcium hydroxide and hydrochloric acid react to form calcium chloride and water as shown in the chemical reaction. If the chemicals are present in exactly the correct ratios to fully use all of the ingredients, how many moles of water would be formed from 5 moles of HCl?

__ Ca(OH)2 + __ HCl → __ CaCl2 + __ H2O

A. 1 moleB. 2 molesC. 5 molesD. 10 moles

50. How many moles are in 75.0 grams of nitrogen gas – N2?

A. 3.00 molesB. 0.333 molesC. 2.68 molesD. 4.52 x 102 5 moles

51. In the reaction, 2 H2 + O2 → 2 H2O, what is the mole ratio of hydrogen to water?

A. 2: 2B. 2 : 1C. 1 : 2D. 4 : 4

52. Baking soda (sodium bicarbonate) is a compound commonly used in baked goods, as a deodorizer in refrigerators and as an antacid. Commercial quantities of baking soda are produced by mixing soda ash dissolved in water with carbon dioxide. Baking soda precipitates as a solid from this method: Na2CO3 + CO2 + H2O → 2 NaHCO3

How many grams of soda ash would be needed to produce 1.00 kg of sodium bicarbonate?

A. 396 gramsB. 631 gramsC. 1270 gramsD. 1590 grams

53. In the reaction 2 H2 + O2 → 2 H2O, how many moles of oxygen are required to fully react with 6.0 mol of hydrogen?

A. 3.0 molB. 6.0 molC. 12.0 molD. 18.0 mol

54. Tell what is wrong with each of the following molecular formulas and write the correct formula.

what is wrong correct formula

SOO (sulfur dioxide)

2HO (Hydrogen peroxide-two hydrogen atoms and two oxygen atoms)

55. Determine the number of electrons and protons contained in an atom of the following elements:

electrons

protons

sulfur

As

element number 24

Hydrogen ion H+

Potassium Cation

56. Write isotope symbols for atoms with the following characteristics.

Contains 18 electrons and 20 neutrons

38Ar 18

A calcium atom with a mass number of 40

40Ca 20

An arsenic atom that contains 42 neutrons

75As 33

57. What is the symbol and name for the element whose average atoms have a mass very close to three times the mass of an average beryllium atom?

Al

58. Determine the molecular weights of the following in amu:

NAME FORMULA MOLECULAR WEIGHT in amu

fluorine (F2) 38

carbon disulfide

(CS2) 76

sulfurous acid (H2SO3) 82

ethyl alcohol (C2H6O) 46

ethane (C2H6) 30

59. The molecular weight is determined for a gas that is known to be an oxide of nitrogen. The value obtained experimentally was 43.98 u. Which of the following is most likely to be the formula of the gas?

A. NOB. N2O

C. NO2

D. NO3

60. Which of the following may not be classified as matter

A. SandB. HeatC. SeawaterD. Our atmosphere

61. Perform the following calculation and express the answer to the right number of significant figures

A. 611 g/mLB. 6.110 x 102 g/mLC. 6.1 x 102 g/mLD. 6 x 102 g/mL

mL

g

2

1222

62. Perform the following calculation and express the answer to the right number of significant figures

A. 3.10B. 3.1073C. 3.1D. 3.11

1.5

957.1389.1

63. Which of the following correctly converts 0.000001546 in scientific notation?

A. 1.546 x 106

B. 1.546 x 105

C. 1.546 x 10-5

D. 1.546 x 10-6

64. Of the following elements, __________ has the most negative electron affinity.

A. P B. Al C. Si D. Cl E. B

65. There are ____ electrons, __ protons, and ___ neutrons in an atom of Xe.

A. 132, 132, 54B. 54, 54, 132C. 78, 78, 54D. 54, 54, 78

66.__________-rays consist of fast-moving electrons.

A. alphaB. betaC. gammaD. X E. none of the above

67. Consider the following selected postulates of Dalton's atomic theory:

(i) Each element is composed of extremely small particles called atoms.(ii) Atoms are indivisible.(iii) Atoms of a given element are identical.(iv) Atoms of different elements are different and have different properties.

Which of the postulates is(are) no longer valid?

A. (i) and (ii)B. (ii) onlyC. (ii) and (iii)D. (iii) onlyE. (iii) and (iv)

68. Isotopes are atoms that have the same number of ___ but differing number of ___.

A. protons, electronsB. neutrons, protonsC. protons, neutronsD. electrons, protonsE. neutrons, electrons

69. An atom of the most common isotope of gold, Au, has ___ p+, ___ no, and ___e-.

A. 197, 79, 118B. 118, 79, 39C. 79, 197, 197D. 79, 118, 79

70. Of the following, the smallest and lightest subatomic particle is the ________.

A. neutronB. protonC. electronD. nucleusE. alpha particle