Name Chem RG Chapter Packet 6 – Covalent Compounds

Period.

Assign Section # Name 10 5

1. Assignment Sheet printed

2. Notes 6.1

3. Notes 6.2

4. Notes 6.3

5. 6.1 Covalent Bonds (WS 4.6 Polar Bonds & electronegativity)

6. 6.2a Ionic Bonding Interactive Activity PBSLearning (2 pages)

7. 6.2b Lewis Dot diagrams WS 5-7

8. 6.2c WS 4.5 More Lewis Structures

9. 6.2d Naming Molecular Compounds WS 9-2

10. 6.3 Molecular Shapes WS 9-6

11. Unit Conversion Tutorial Part 3

Ch 06 Test Review (turn in separately for graded points)

(Total Points = 11 x 10 = 110)

Notes:

1. Your lab report is turned in by itself and receives a separate grade. 2. Your test reviews are graded separately. 3. Website: http://chem-rg-flipped.santiago.groupfusion.net/

EVIDENCE (after you take notes.) You should have at least 4 types of evidence for each set of notes. 1. Number new concepts 1,2,3…/A,B,C… 2. Delete/Cross out unimportant information Unimportant

3. Circle vocab/key terms

4. Identify points of confusion ?

5. Underline/Highlight main Ideas Main Ideas 6. Identify information to be used on a test, essay… *

7. Fill in gaps of information. Reword or paraphrase. ^ 8. Create visuals/symbols of important

information Visuals/symbols

Key Terms

Ch 6 B10 Relative Solubilities of the Transition Elements Transition elements are in periods 4, 5, and 6 (between groups 2 & 13). As the atomic number increases across a row in this section of the table, no new valence electrons are added. Instead, electrons are added to inner energy levels. So, transition element properties are similar across a row as well as down a column. Often, the properties of transition element properties in a row are more alike than in a column. This is not so for non-transition elements.

In this lab, you will evaluate the solubility of compounds of iron, copper, zinc, and silver in both water & acid. Iron, copper, and zinc are in the same row of the periodic table; copper and silver are in the same column. You will mix these transition elements with five different reactants and observe whether an insoluble compound (precipitate) forms. For those that form precipitates, you will investigate how the precipitate behaves in acid. After recording your findings, you will decide whether each new compound is soluble or insoluble in water and to what extent it dissolves in acid. You can then look for trends related to the positions of the elements in the periodic table. OBJECTIVES • Observe the reactions of some transition-element ions with five anions.

• Deduce the solubility of transition-element compounds in water and in acid. • Compare solubilities of elements in same column and in the same row of the periodic table.

PROCEDURE - See ast page of lab for helpful notes

CAUTION: Nitric acid, HNO3, is corrosive and caustic. Avoid contact with eyes and skin. If any should spill on you, immediately flush the area with water and notify your teacher. 1. Copy the Data Table into your lab notebook. 2. Flow-chart this procedure in your lab notebook. 3. Place two drops of each transition-element solution in the appropriate well on the microplate. These

solutions contain positive ions. Be careful; silver nitrate, AgNO3, will stain skin and clothing. There should be five boxes in a row for each transition element.

4. Add two drops of each of the reactants, which contain negative ions, to each of transition-element solution. Do not allow the dropper to touch the transition-element solutions!

5. Immediately after adding each reactant solution, record your observations in the Data Table section labeled 0 min. If no reaction occurs, write NR. If a precipitate f o r m s , record its color.

6. Wait 5 min, and then record any changes the Data Table section labeled 5 min. If no change occurs, w r i t e same. 7. To each mixture in which a precipitate formed, add 1 to 4 drops of 1.0 M nitric acid. Write “clear” in the acid

section if the precipitate disappeared. Write PC if the precipitate partially disappeared & “same” if no change. Record any color change.

8. Clean all apparatus and your lab station. Return equipment . Put chemicals & solutions in disposal containers.

Analysis Organizing Data and Analyzing Results

1. Study your Data Table ((on the next page) carefully. Then complete the Solubility Chart below it. a . Write S if the mixture is soluble in water (no reaction) b. Write PS if it is partially soluble in water. (Assume a mixture is partially soluble in water if it

was clear at 0 min but became cloudy after 5 min.) c. Write SA if the mixture is soluble in acid but not in water. d. Write PSA if it is partially soluble in acid but not in water. (Assume a mixture is partially

soluble in acid if the precipitate partially dissolved after adding nitric acid, HNO3) e. Write I if the mixture is insoluble in water and acid.

DATA TABLE:

Transition ions

Reactant ions Cl1-

C2O4

2- SO4

2-

SCN1-

Fe(CN)6

4-

Cu2+ 0 min

5 min acid

Fe3+ 0 min

5 min acid

Ag+ 0 min

5 min

acid

Zn2+ 0 min 5 min acid

SOLUBILITY CHART (fill in after the lab. Use your data table & write “S”, “PS”, “SA”, “PSA” or “I” according to the directions in “Organizing Data” #1 on the previous page ) Transition ions

Reactants Cl1- C2O4

2- SO42- SCN1- Fe(CN)6

4-

Cu2+

Fe3+

Ag+

Zn2+

Analyzing Results. 2. Which transition-element ion(s) formed the greatest number of soluble compounds? 3. Which transition-element ion(s) formed the smallest number of soluble compounds 4. Copper and silver are in the same column. Iron, copper, & zinc are in the same ro w. According to your

Solubility Chart, are solubilities more similar across the row, or down the column, or neither? 5. Use your Data Table and Solubility Chart to identify each of the following unknown (+ ) ions.

a. Forms a white precipitate with Cl1- b. Forms a precipitate with at least 4 reactant ions.

B10 Solubility Trends Lab Notes

Ch06 Covalent Compounds (Holt) pp 6.1 Covalent Bonds

• Explain the role & location of electrons in a covalent bond. • Describe the change in energy & stability when a covalent bond forms. • Distinguish between nonpolar and polar covalent bonds based on electronegativity differences. • Compare physical properties of different bond types and relate to electronegativity

Types of Chemical Bonding Ionic - results from the __________ __________ between large numbers of __________ and __________.

Covalent - results from the __________ of electron __________ between two atoms.

Metallic - from chemical attraction between __________ atoms and the ______ of e-s surrounding them.

Ionic or Covalent? Bonding atoms are rarely purely ionic or purely covalent. The % character of ionic or covalent bonding can be estimated from the __________ in electronegativities. See Fig. 6, p. 194 to solve the problems.

Types of Covalent Bonds Nonpolar - bonding electrons are shared __________, resulting in balanced distribution of electrical charge.

Polar - __________ distribution of electrical charge.

Polar-covalent bond - the bonded atoms have an unequal attraction for the shared electrons.

Differences in Electronegativity 0.0 to 0.3 -- Nonpolar-covalent (less than 5%) 0.3 to 1.7 -- Polar-covalent (5% to 50%) 1.7 to 3.3 -- Ionic (more than 50%)

Covalent Bonding & Molecular Compounds Molecule - __________ group of atoms held together by __________ bonds.

Molecular compound - a chemical compound composed of molecules.

Chemical formula - Shows relative numbers by using atomic __________ and __________.

Molecular formula - Shows types and numbers of atoms in a single molecule.

Diatomic molecule - molecule with only __________ atoms.

The electrons in each atom are __________ to the nucleus of the __________.

The electrons __________ each other, The nuclei __________ each other.

They reach a distance with the ________possible energy. The distance between is the _______ ________.

Bond Energy - energy required to break a chemical bond and form neutral isolated atoms.

The Octet Rule Noble gases don’t ________. Possess minimum energy on their own because of their e- configurations.

Outer __________ orbitals completely filled.

Octet Rule - Compounds form so each atom _______, ________or ________electrons to get an ________in its __________ __________ energy level.

Covalent Bonding

Electrons are __________ by atoms. Sharing is caring and caring is __________

There are two extremes. In between are ________covalent bonds where the e-s are _______shared evenly.

One end is __________ positive, the other __________. Indicated using small delta δ.

Covalent bonds __________ hold onto their valence electrons. They __________ give away electrons to bond.

Still want noble gas configuration. Get it by __________ valence electrons with each other.

By sharing __________ atoms get to __________ the electrons toward noble gas configuration.

Covalent is __________ to __________.

Metallic Bonds Metals hold onto their valence electrons very __________.

Think of the metals as positive ions floating in a __________ of negative electrons.

__________ are free to move through the __________. So, metals __________ electricity.

Metal Properties Malleable - can be __________ into shape. Ductile - can be drawn into ________. Shiny

6.2 Drawing and Naming Molecules • Draw Lewis structures to show valence electron arrangement in molecules and polyatomic ions. • Explain the difference between single, double, and triple bonds. • Draw resonance structures and know when they are required. • Name binary inorganic compounds using prefixes, roots and suffixes.

Keeping Track of Electrons The e-s responsible for the __________ properties of atoms are those in the __________ energy level.

__________ electrons - The __________ electrons in the __________ energy level.

Core electrons - those in the energy levels __________ (inner electrons).

Electron Dot diagrams Write the symbol. Put one dot for each valence electron. Don’t pair up until they have to.

Electron Dot Structures Symbols of atoms with dots to represent the valence-shell electrons 1 2 13 14 15 16 17 18 H• He: • • • • • • • • • • • Li• Be• • B • • C • • N • • O • : F • :Ne : • • • • • • • • • • • • • • • • • • • Na• Mg• •Al• • Si • •P• •S• :Cl • :Ar : • • • • • • • •

Write the electron dot diagram for:

Na

Mg

C

O

F

Ne

He

Single Covalent Bond

A sharing of __________ valence electrons. Only between __________

nonmetals to nonmetals = __________

__________ to nonmetals = ionic

Rules __________ the valence electrons.

Use a __________ to form a __________ between each pair of atoms.

Arrange the __________ to fulfill the __________ rule (except for H and the __________).

Can use a __________ instead of a shared pair.

Try CH3I and NH3 in the space below

Multiple Covalent Bonds Sometimes atoms share __________ than one pair of valence electrons.

A __________ bond is when atoms share two __________ of electrons (__________ electrons).

A triple bond is when atoms share __________ pairs of electrons (__________ electrons).

Carbon dioxide – COPY THE EXAMPLE INTO THES NOTES

How to draw Lewis Structures pp __________ up all the valence electrons. __________ up the total number of valence electrons to make all atoms ________. (8 for all but H) Subtract. Divide by __________ This tells you # of __________ - draw them. Fill in rest of the valence electrons so atoms get their __________ gas configuration. (happy-have) / 2 = # of bonds

Example HCN – DO THIS ON YOUR NOTES AS WE DO IT IN CLASS HCN C is central atom

N - has __________ valence electrons wants __________

C - has __________ valence electrons wants __________

H - has __________ valence electrons wants __________

HCN has 5+4+1 = __________

HCN wants 8+8+2 = __________ (to be __________)

(18-10)/2= __________ bonds

So, __________ atoms with __________ bonds - will require __________ bonds (but, not to H -- why?)

Put in the two __________ bonds

Still need 2 more bonds (to be happy)

These must go between C and N (why?)

Polyatomic Ions Charged group of __________ bonded atoms. E.g., NO3

1-, SO42-, NH4

1+.

Lewis structures: Follow __________ steps __________:

If __________, __________ electrons = to the __________. If cation, subtract e-s = to the charge. Use brackets. You Try Lewis Dot Notation PO4

3- NH41+ IBr

Cl2O ClO1-

Resonance When __________ than one Lewis diagram with the same connections are possible. Use double arrows to indicate it is the “__________” of the structures. Try NO3

1- IN YOUR NOTES HERE

Covalent Names & formulas

Easier than ionic naming and formulas Molecular compound’s name tells you the number of atoms. It uses prefixes to tell you the number. 1 mono- 2 di- 3 tri-

4 tetra- 5 penta- 6 hexa-

7 hepta- 8 octa- 9 nona-

10 deca-

To write the name write two words One exception is we don’t write mono- if there is only one of the __________ element. Write least electronegative atom first

Name these

N2O

NO2

Cl2O7

CBr4

CO2

BaCl2

Write formulas for these diphosphorus pentoxide

tetraiodine nonoxide

sulfur hexaflouride

nitrogen trioxide

Carbon tetrahydride

phosphorus trifluoride

aluminum chloride

6.3 Molecular Shapes

• Predict a molecule shape using VSEPR • Determine the polarity of a molecule from its shape.

Molecular Geometry Molecular properties depend on

(1) __________ of atoms and (2) __________.

Molecular polarity - the __________ distribution of __________ charge (vs. atomic charge).

VSEPR Theory Valence Shell Electron Pair Repulsion. Predicts 3-dimensional geometry of molecules.

The __________ tells you the theory.

Valence shell - __________ s & p electrons.

Electron Pair Repulsion - electron pairs try to get __________ as possible.

Can determine the __________ of bonds (geometry).

VSEPR Based on the number of pairs of __________ electrons both __________ and unbonded. Unbonded pairs are called __________ pairs.

4 atoms bonded to central Basic shape is __________. (AB4) A pyramid with a triangular base. Same shape for everything with 4 pairs of e-s.

3 bonded with 1 __________ pair Still basic tetrahedral, but you can’t __________ the electron pair (still takes up space). (AB3E)

So, shape is called __________ __________.

2 bonded with 2 lone pair

Still basic tetrahedral but you __________ the 2 lone pairs. (AB2E2)

Shape is called bent __________.

__________ atoms to central, no lone pair

The farthest you can the 3 electron pairs apart is 120º. (AB3)

Shape is flat and called trigonal __________.

2 atoms no lone pair With three atoms the farthest they can get apart is 180º.

Shape called __________. (AB2)

Predicting a VSEPR Structure

1. Draw Lewis structure. Do not assume the number of e- pairs. Multiple bonds count as one pair!!! 2. Put lone pairs as far apart as can. 3. Determine positions of atoms from the way electron pairs are shared. 4. Determine the name of molecular structure from positions of the atoms (vs. the electron pairs)

VSEPR Use VSEPR theory and your gumdrops to predict the shapes of . . . CCl4,

HCN,

NO31-

Molecular Polarity & Dipole-Dipole Forces Dipole - created by equal but opposite charges that are separated by a short distance. Dipole-dipole Forces: Short-range forces of attraction between polar molecules.

We see these in __________ covalent bonds.

Polar Molecules Molecules with a slightly positive and a slightly negative end Requires two things to be true 1. The molecule must contain polar bonds (determine from differences in electronegativity). 2. Symmetry cannot cancel out the effects of the polar bonds. (Must determine geometry first.)

Polar Molecules 98% of the time, the molecule is polar if it has _________bonds & there is at least one __________ pair. Is it polar? Draw the structure and follow the rule just above. HF H2O NH3 CCl4 CO2

6.1 Worksheet: Covalent Bonds Use  the  electronegativity  table  in  your  notes  (or  see  p.  194)  and  the  bonding  rules  (see  your  notes).    

Atoms   Electronegativity  Difference  

Bond  type  (Ionic,  polar  covalent  or  nonpolar  covalent)  

Most  electronegative  atom  

H  and  I        

S  and  O        

K  and  Br        

Si  and  Cl        

Se  and  S        

C  and  H        

6.2a Ionic & Covalent Bonding Interactive Activity PBSLearning (2 pp.) Go to http://www.pbslearningmedia.org/shared/blachman/chemsharks/

Ionic Bonding, also do Covalent Bonding

Ionic Bonding Interactive Activity Charges that are alike will __________each other whereas charges that are opposite will ________ each other.

Therefore, ionic compounds need both a ______________ ion and a ___________ ion.

_______________ usually make positive ions and _____________ usually make negative ions. Therefore,

ionic bonds are usually formed when _____________ bond with _____________.

When sodium loses an electron it becomes a _______________ charged ion.

When chlorine gains an electron it becomes a ____________________ charged ion.

These two ions are held together because of their ________________ charges.

In ionic compounds the formula tells us the _______________ between the ions in the crystal. It does not

mean that they are individual _______________________.

Covalent Bonding Interactive Activity How do the hydrogen atoms interact with each other? __________________________________________

________________________________________________________________________________________

How is the movement of the electrons different when you move the atoms close to each other?

________________________________________________________________________________________

What happens if you try to move the atoms very close to each other? ____________________________

________________________________________________________________________________________

Where do the shared electrons spend most of their time? _______________________________________

In a covalent bond both atoms ______________ or _______________ over the electrons.

In general, covalent bonds tend to form between______________.

Atoms are most stable when what two things occur? ___________________________________________

________________________________________________________________________________________

When atoms share two pairs of electrons we call it a _____________ bond, where a total of

________________ electrons are shared.

When atoms share three pairs of electrons we call it a _____________ bond, where a total of

________________ electrons are shared.

When atoms share one pair of electrons we call it a _____________ bond, where a total of

________________ electrons are shared.

The strongest bonds are usually _____________ bonds and the weakest bonds are usually

________________bonds.

When naming a covalent bond the ending of the second element is usually changed to __________.

Why are prefixes added to an elements name? _______________________________________________

mono- means _____ di- means _____ tri- means _____

tetra- means _____ penta- means _____ hexa- means _____

What is the only exception when using a prefix when naming a covalent compound?_______________

________________________________________________________________________________________

__

Give the name for the following: Give the formula for the following:

N2O ____________________________ disulfur dichloride __________

NO2 ____________________________ sulfur dioxide __________

N2O4 ____________________________ disulfur trioxide __________

N2O3 ____________________________ disulfur monoxide __________

NO ____________________________ sulfur trioxide __________

6.2b Worksheet: Drawing and Naming Molecules (Lewis dot Diagrams, Chem Worksheet 5-7)

6.2c Worksheet: More Lewis Structures Draw the following covalent compounds using Lewis Dots (Use “happy – have ÷ 2)

a. CH4 b. H20 c. NH3

Double Bonds…..(4 e-‘s are being shared or 2 bars) Be sure to balance & pair up the lone pairs! d. N2F2 e. 02 f. C02 (2 sets of double bonds!) Triple Bonds…..(6 e—‘s are being shared or 3 bars) Be sure to balance & pair lone pairs! g. N2 h. HC2Cl i. C2H2 Ions Lewis Dots j. F- k. Mg2+ l. P3- Polyatomic Ions

m. SO42- n. H3O+ o. NH4

+ Resonance (Show BOTH ways the Lewis Dots can be shown)

p. O3 q. SO2

6.2d Worksheet: Naming Molecular Compounds (Chem Worksheet 9-2)

6.3 Worksheet: Molecular Shapes (WS 9-6)

Draw the Lewis structure and use VSEPR to predict the shape of the following: Formula Lewis Structure Shape (happy-have) / 2 = # of bonds NH2Cl NOCl (N is central atom double bond between N & O) NO3

1- NH4

1+

Unit Conv. Tutorial Part 3 Name: ______________________________ Period: _______

• Go  to  the  following  website:     http://joneslhs.weebly.com  

• Click  on  the  Learn  button  on  the  left.      Read  the  5-­‐minute  tutorial  first.  When  you  think  that  you  understand  the  idea,  go  back  to  the  Main  Menu  and  click  on  Double  Unit  Conversions  and  then  on  Cubed  and  Square  Conversions  and  complete  this  worksheet.  

• Read  the  directions  on  the  first  problem  to  see  how  to  get  started.    Work  through  the  challenging  

problems  recording  your  answer  below  for  each  one.      Don’t  forget  units!    Check  your  answers  online  on  the  website.      SHOW  YOUR  WORK!    

Double Unit Conversions 1. Calculated  Answer:    

       

2. Calculated  Answer:      

     

3. Calculated  Answer:    

4. Calculated  Answer:    

5. Calculated  Answer:    

6. Calculated  Answer:        

Cubed and Squared Conversions 1. Calculated  Answer:      

     

2. Calculated  Answer:    

       

3. Calculated  Answer:    

       

4. Calculated  Answer:          

Name ___________________________________________ Period ________

Chapter  6:  Review  -­‐  Turn  in  Separately  for  Points  –  Hint:  Look  at  skeleton  notes    

The  electrons  are  involved  in  bonding  are  called  the  _________________  and  can  be  found  in  the  _____  and  _____  

orbitals  

The  chemistry  (reactivity)  of  an  element  is  mostly  determined  by  the  number  of  ____________  electrons  

For  the  main  group  (groups  1-­‐2,  and  13-­‐18)  elements,  the  number  of  valence  electrons  can  be  determined  by  the  

_______________  number.  

Molecular  compounds  have  ___________  bonds  because  their  electrons  are  _____________  between  them.    This  

means  that  they  will  have  ________  melting  and  boiling  points.    Elements  in  a  covalent  compound  are  often  

found  on  the  _______  side  of  the  periodic  table  and  occur  when  a  ____________  bonds  to  a  _____________.    

They  never  conduct  electricity  and  therefore  make  good  ______________s.    

Metallic  compounds,  have  ___________  bonds  because  their  electrons  are  _______  between  them  like  a  ______  of  

electrons.    This  means  that  they  will  have  ________  melting  and  boiling  points.    Elements  in  a  metallic  

compound  are  often  found  _____________  on  the  periodic  table  and  occur  when  a  ____________  bonds  to  a  

_____________.    They  always  _______  electricity.    They  are  often  shiny,  ______________  (which  means  that  

they  can  be  hammered  into  sheets),  and  ductile,  which  means  they  can  be  drawn  into  a  ____________.  

In  covalent  compounds  the  formula  does  indicate  the  number  of  each  atom  that  is  present.    Because  you  cannot  

predict  a  covalent  formula  in  the  same  way  that  you  can  predict  an  ionic  formula,  it  is  necessary  to  use  _____________  

in  the  name  to  indicate  the  number  of  each  atom  in  the  bond.    However,  the  basic  naming  rules  still  apply,  therefore,  

the  name  of  the  first  element  still  stays  the    ________  and  the  name  of  the  second  element  still  ends  in  ________.  

Large  biological  molecules  often  have  the  element,  _________,    as  their  center  atom  and  are  made  up  of  

____________  bonds.  

Determine  the  bond  type  for  the  following  compounds:    Ionic  (I),  Covalent  (C)  or  Metallic  (M)  

CaCl2  ________      NH3  ________      Cl2  ________      CF4  ________      Li2S  ________      Cu  ________      Ba(OH)2  ________  

Which  of  the  above  has  the  lowest  boiling  point?  (hint:  think  of  type  of  bonding):    

Draw  the  Lewis  Structure  for  the  following  atoms:  

Li        Be     B     C     N     O     F     Ne  

 

 

When  drawing  a  Lewis  Structure,  a  lone  pair  means  those  electrons  are  not  __________  to  another  atom.  

When  one  pair  of  electrons  is  shared  between  two  atoms  it  is  called  a  __________  bond,  two  shared  pairs  make  up  a  

__________  bond  and  three  shared  pairs  make  up  a  _______________  bond.  

Draw  the  Lewis  Structure  for  the  following  compounds:  

CO         NH3         C2H4       SO42-­‐