Chemistry: Exam Two

21. What are the two types of polymerizations?

A. Addition and condensation polymerizations B. Condensation and displacement polymerizations C. Addition and decomposition polymerizations D. Condensation and substitution polymerizations

22. Which of the following is a monomer of natural rubber?

A. Isoprene B. Hexamethylene diamine C. Styrene D. Ethylene terephthalate

23. The component of the environment consisting earth's upper outer most skin, and accessible to human beings is known as _____.

A. atmosphere B. hydrosphere C. lithosphere D. biosphere

24. Consider the following steps that occur during the nitrogen cycle:

Step 1: Reduction of nitrate by microbial action
Step 2: Fixation of nitrogen by bacteria and algae
Step 3: Nitrification by nitrosomas and nitrobactria
Step 4: Denitrification of nitrate with acid and formladyde

Which of the following is the CORRECT sequence in the nitrogen cycle?

A. Step 1 → Step 3 → Step 4 → Step 2 B. Step 2 → Step 3 → Step 1 → Step 4 C. Step 1 → Step 2 → Step 3 → Step 4 D. Step 2 → Step 3 → Step 4 → Step 1

25. Some hazardous substances damage and create unwanted changes in air, water, soil or any other natural resource. The resulting change created is known as:

A. global warming B. greenhouse effect C. pollution D. afforestation

26. Which of the following descriptions of the property of a covalent compound is CORRECT?

A. Most covalent compounds are solids at room temperature. B. Covalent compounds have low melting and boiling points. C. Covalent compounds are non-volatile. D. Most covalent compounds are soluble in water.

27. The attractive force between molecules is known as __________

A. intermolecular force B. nuclear force C. intramolecular forces D. lattice force

28. The hybridization of the central atom xenon (Xe) in xenon tetraflouride, XeF₄, is sp³d². Which of the following is the shape of XeF₄?

A. Square planar B. Octahedral C. Seesawa shape D. Tetrahedral

29. Which of the following is the CORRECT electron configuration of a peroxide ion, O₂^2-?

A. (σ_1s)²(σ*_1s)²(σ_2s)²(σ*_2s)²(π_2py² = π_2pz²)(π*_2py² = π*_2pz²) B. (σ_1s)²(σ*_1s)²(σ_2s)²(σ*_2s)²(π_2py² = π_2pz²)(π*_2py)² (σ*_2z)² C. (σ_1s)²(σ*_1s)²(σ_2s)²(σ*_2s)²(π_2py² = π_2pz²) D. (σ_1s)²(σ*_1s)²(σ_2s)²(σ*_2s)²(π_2py² = π_2pz²)(π*_2x)²

30. Consider the following reaction between nitrogen (N₂) and oxygen (O₂):
N₂(g) + O₂(g) → 2NO (g)
If the rate of disappearance of N₂ is 2.5 x 10^-6 M/s, what is the rate of reaction for the formation of NO?

A. 1.25 x 10^-5 M/s B. 5.0 x 10^-6 M/s C. 2.50 x 10^-6 M/s D. 2.50 x 10^-5 M/s

31. Given the following heterogeneous reaction:
CaCO₃ (s) ⇌ CaO (s) + CO₂ (g)
What is the equilibrium constant expression for the above reaction?

A. Kc = ([CaO][CO₂] )/([CaCO₃]) B. Kc = [CO₂] C. Kc = [CaO]/[CaCO₃] D. Kc = [CaO][CO₂]

32. Which of the following statements is CORRECT regarding the properties of monocarboxylic acids?

A. Heating of carboxylic acid with alcohol produces salt and water. B. Carboxylic acids react with strong bases to form esters and water. C. The hydrolysis of carboxylic acids in water produces an ester and water. D. Carboxylic acids react with active metals to form salt and hydrogen gas.

33. What is the scientific notation for 0.000055?

A. 5.5 x 10^-4 B. 55 x 10^-5 C. 5.5 x 10^-6 D. 55 x 10^-7

34. A water molecule has two bond pairs and two lone pairs of electrons. Which of the following is CORRECT about these pairs of electrons?

A. Lone pair - lone pair repulsion is exactly identical with bonding pair - bonding pair repulsion. B. Bonding pair - lone pair repulsion is greater than lone pair - lone pair repulsion. C. The repulsion between the two lone pairs is greater than the repulsion between the two bonding pairs. D. The repulsion between the two bonding pairs is greater than the repulsion between the two lone pairs.

35. Which of the following CORRECTLY describes conjugate acids and conjugate bases?

A. Conjugate base has one more hydrogen and one fewer minus charge than the corresponding base. B. Conjugate acid has one fewer hydrogen and one more minus charge than the corresponding acid. C. Conjugate base is a species formed after removal of a proton from an acid whereas conjugate acid is formed after addition of a proton to a base. D. Conjugate acid is a species formed after a removal of a proton from a base whereas conjugate base is formed after addition of proton to an acid.

36. Consider the following reaction of zinc carbonate, ZnCO₃:
ZnCO₃(s) → ZnO (s) + CO₂ (g)
The chemical reaction that takes place during the conversion of ZnCO₃ is classified as __________

A. single displacement reaction B. double displacement reaction C. combination reaction D. decomposition reaction

37. Given the following reaction:
CaCO₃ + HCl → CaCl₂ + CO₂ + H₂O (unbalanced)
If 40 g of CaCO₃ reacts with 50 g of HCl, which substance is the limiting and which is the excess reagent? (Atomic Mass Ca=40 g/mol, C=12 g/mol, O=16 g/mol, H=1 g/mol and Cl=35.5 g/mol)

A. CaCO₃ is limiting and HCl is excess reactants. B. CaCO₃ is limiting and CaCl₂ is excess reagents. C. HCl is limiting and CaCO₃ is excess reactants. D. HCl is limiting and CaCl₂ is excess reagents.

38. A sample of a certain gas has a volume of 100 L at 27 °C and 750 torr. The gas is expanded to a volume of 250 L at 200 torr. What is the final temperature of the gas?

A. -273 °C B. -173 °C C. -73 °C D. -83 °C

39. Which of the following is a CORRECT explanation of the given term?

A. Heat of vaporization is the energy required to convert one gram of a solid to a gas at its boiling point. B. Normal boiling point is the temperature at which the liquid starts to be converted to the gaseous state. C. Condensation is the process by which a liquid changes to a gas at the boiling point of the liquid. D. Boiling point is the temperature at which the vapor pressure of the liquid equals the atmospheric pressure.

40. Which of the following is the general formula of alkenes?

A. C_nH_2n B. C_nH_n C. C_nH_2n+2 D. C_nH_2n-2

Chemistry Exam Two

Exam Results