SCIENCE 111 TEST 2 REVIEW QUESTIONS

March 7, 2005

(In multiple-choice questions, there can be more than one correct answer)

 

5                     Vinegar is a dilute solution of acetic acid and water.  If you had a container of pure acetic acid, explain how you would determine both the mass and the volume of one mole of acetic acid? (The molecular formula of this compound is C2H4O2)

 

 You would add the atomic weights of each atom in the compound times the number of atoms of each and that would equal the mass in grams of one mole of acetic acid (or Avogadro’s number of acetic acid molecules).  You would put a beaker on the scale, tare the beaker, and fill it with acetic acid until it reached that mass. Then you would see what the volume in milliliters was.

 

 

 

7                     For the element argon tell the

A        Element symbol Ar

B         Atomic number 18

C        Atomic weight 39.948

D        Number of protons 18

E         Average number of neutrons 39.948 – 18 =

F         Number of electrons in a neutral atom 18

G        Whether it is a metal, nonmetal, or semiconductor

H        Whether you would expect it to be reactive or nonreactive

 

 

1                     8                     Which of the following are ways that elements are arranged on the periodic table?

A        Solutions, suspensions, and heterogeneous mixtures

B         Ions and isotopes

C        Molecules, compounds, and elements

D        Solids, liquids, gases

E         Chemical behavior, number of protons, and atomic radius

 

 

2                     9                     Differences between metals and nonmetals include:

A        A        Metals tend to lose electrons and nonmetals tend to gain electrons

B         B         Metals form negative ions and nonmetals form positive ions.

C        C        Metals comprise the left 2/3's of the periodic table and nonmetals are on the right side of the table.

D        D        Sometimes semi-conductors act like metals, sometimes like nonmetals.

 

 

3                     10                 Which of the following statements about the elements is correct?

A        A        Alkaline earth metals are very stable because all of their outermost electron shells are filled to capacity.

B         B         Alkali metals are also called the rare earth metals.

C        C        Alkali metals are the most reactive metals.

D        D        Noble gases are the most reactive nonmetals.

E         E         Halogens rarely react with metals.

 

 

 

 12                When you mix lipids and water (as with phospholipids in the plasma membrane), the lipids do not go into solution.  Which statement below is the best explanation of this phenomenon?

A       A       Lipids and water are both polar molecules so they repel each other.

B       B       Lipids and water are both nonpolar molecules so they repel each other.

C       C       Lipids are polar and water is nonpolar.

D       D       Lipids are nonpolar and water is polar.

E        E        Both A and C

 

 

 

12                14                Which statement below is true of an ionic bond?

A       A       is formed by non-metallic elements transferring electrons to one another.

B       B       is formed by metallic elements transferring electrons to one another.

C       C       Electrons lost by a metal are gained by a nonmetal.

D       D       Two atoms share two pairs of electrons.

E        E        An atom of a metal bonds with an atom of a noble gas.

 

 

13                15                A covalent bond in which there is unequal sharing of a pair of electrons is called a______? Why?

A       A       Hydrogen bond.

B       B       Double covalent bond.

C       C       Polar covalent bond.

D       D       Nonpolar covalent bond.

 

 

14                16                Which of the following is a property of an acid?

A       A       Feels slippery to the skin.

B       B       Is anything above 7 on the pH scale.

C       C       Has a bitter taste.

D       D       Donates protons when dissolved in water.

E        E        Donates hydroxide ions (OH-) when dissolved in water

 

 

 

 

15                18                What are the boiling and freezing points of distilled water in both Fahrenheit (212 and 32) and Celsius (100 and 0)?

 

16                19                What kind of bond will each of the following groups of elements most likely form?  Give the molecular formula and explain why.

A       A       Nitrogen + Oxygen, covalent, N2O

 

B       B       Hydrogen + Oxygen covalent, H2O

 

C       C       Hydrogen + Chlorine ionic, HCl

 

D       D       Potassium + Chlorine ionic, KCl

 20                For the following molecular gases, write the electron dot notation, structural formula and molecular formulas:

A       Hydrogen,  H2

 

B       Nitrogen  N3

 

C       Oxygen  O2

 

D       Chlorine  Cl2

 

E        Water vapor H2O

 

F        Methane (one carbon, four hydrogens) CH4

 

 

21                What is the correct molecular formula when the following groups of elements are combined?  Explain how you know.

A       aluminum and fluorine AlF3

 

B       Aluminum and oxygen Al 2 O3

 

C       Calcium and oxygen CaO

 

 

17                22                Acetylene is a colorless gas used in metal cutting and welding (as an acetylene torch).  A molecule of acetylene contains two atoms of hydrogen and two atoms of carbon.  For this molecule:

A       What kinds of bonds hold the hydrogen and carbon together. covalent

B       Draw the electron dot notation

C       Draw the structural formula

D       Write the molecular formula H2C2