Chemistry 30  Unit II  Nature of the Substance         Donkin

Each of these statements or questions is followed by four responses. Choose the correct response in each case.

1.  Chemical bonds are the result of...

    a) electron-electron repulsion
    b) proton - proton attractions
    c) attraction of an atom's nucleus for its valence electrons
    d) simultaneous attractions of shared electrons for two nuclei.

2.  An ionic bond is usually formed between...

    a) two nonmetals
    b) two metals
    c) a metal and a nonmetal
    d) a metalloid and a nonmetal

3.  What is the correct formula for the ionic compound formed when magnessium reacts with fluorine ?

    a) MgF    b)  Mg₂F        c)  MgF₂     d)  Mg₂F₃

4.  What is the formula of the ionic compound formed when element X  ( three valence electrons ) reacts
      with element Y ( six valence electrons )?

    a) X₂Y₃         b) XY         c)  X₂Y        d) X₃Y₂

5.  Which of the following is a property of ionic compounds?

    a)  Their solids conduct electricity.
    b)  They are usually gases or liquids at room temperature.
    c)  They have high melting points.
    d)  They are soft and waxy.

6.  Which of the following is a property of molecular compounds?

    a)  They have low boiling points.
    b)  They are hard and brittle.
    c)  Their molten state conducts electricity.
    d)  They have high melting points.

7.  Element X has an electronegativity of 3.5 and element Y has an electronegativity of 3.0.
     The most probable type of bond between X and Y is :

    a) nonpolar covalent
    b) polar covalent
    c) ionic
    d) unpredictable

8.  Which of the following contains an atom that does not obey the octet rule?

    a) MgO        b) IF₅        c) CCl₄        d)  KCl

9.  What is the predicted shape of PH₃ ?

    a)  tetrahedral
    b)  trigonal planar
    c)  trigonal pyramidal
    d)  linear

10.  What is the predicted shape of HCN ?

    a)  trigonal pyramidal
    b)  trigonal planar
    c)  tetrahedral
    d)  linear
 

Part II   Nature of the Substance

Use the following compounds:   CrMo,  SiC,  BBr₃,  Cl₂,  NaI,  B,  Au,  Ne,  Ba,  PCl₃
 

1.  Which are molecular in nature: __________________________________________________

2.  Which are ionic in nature: ______________________________________________________

3.  Which are solids at room temperature: _____________________________________________

4.  Which will readily dissolve in water: _______________________________________________

5.  Which are covalently bonded substances with high melting points: _________________________

6.  Which will conduct electricity in a solid state: ________________________________________
 
 

 Part III   Nature of the Substance

1. CO₃^-2

2. SeH₂

3. CCl₄

Part IV   Nature of the Substance

1. silver (I) fluoride
 
 
 
 
 

2. nitrogen trihydride
 
 
 
 
 

3. iodine heptafluoride
 
 
 
 
   

Part IV   Nature of the Substance - Short Answer Questions

1. List three intermolecular forces and describe each.

2. Metallic compounds are held together with __________ bonds. Explain how this type of bond
is responsible for three properties of metals.

3. Br. HONClIF is used to remember diatomic elements. Why are these elements diatomic and
other not ?

[Solutions]
[Chemistry 30]

answers need to be checked