Ionic Compound

Ionic compounds are basically defined as being compounds where two or more ions are held next to each other by electrical attraction

Ionic Compounds

This is a summary of the past and present nomenclature or naming conventions for ionic compounds

Naming Compounds

An ionic compound is one in which at least two of the elements or compounds in the group are oppositely-charged ions held together

Ionic Compounds

Ionic compounds generally are very hard and have very high melting points. They are solids at room temperature

Face Centered Cubic

When metals react with non-metals they form an ionic compound. Ions have a charge because electrons are lost or gained in forming an ionic bond.

Showing posts with label covalent. Show all posts
Showing posts with label covalent. Show all posts

Tuesday, August 9, 2011

Examples of Covalent Bond



If we encounter the world, we have a huge lack of knowledge of the structures around the world in one easy movement unit aggregation is the difference between the atoms. Electromagnetic force to hold atoms together to form molecular compounds that come into an even larger molecules and polymers that are resistant as possible. This complexity reduction is likely that the electromagnetic forces between charged particles. Etching of atoms turns to pity, or to sell the source of electrons to create a network of molecules possible. Bond between the atoms can be covalent or ionic bond. They have two varieties of grass containing alkaline sizing. The purpose of this essay is an essay required of the alkaline-containing covalent attachment of the screen examples of the deposit.

What is a covalent bond?

We must first determine what is a covalent bond, before studying a few examples of this link. Because we have studied the theme of the covalent bond, we pretend we already know what an atom and has been reported with the atomic structure. Covalent atoms deposit is formed when you divide the unit, or calibration times between the electrons in the other. These shared electrons come from the span of money between the atoms, which keeps them together and only units that we chose to be a molecule. These shared electrons are the valence electrons of atoms spinning in their shells extreme.

Each atom, forming a covalent hand money to try to capture the courage, which has extremely filled electron orbitals of the atoms, which are still empty. As two atoms come together and share electrons, deposit, together with the electromagnetic force to conquer that between atomic nuclei and electrons within the municipality. In addition, the force between the combs of the electrons orbiting the two atoms, which causes the proton to get distorted. While the two atomic nuclei are excited about the town of electrons arc, a deposit is connected between the two atoms.

Depending on the similarities in the nucleus or Electronegativity (tendency to capture electrons from atoms), a single span Similarly, the electrons may or may not be evenly distributed. If they were distributed unevenly, the proton becomes "Polar" in the sense that the imbalance in spending towards the interior. Let's look at some examples of covalent payment in the next section. Understand the difference between covalent and ionic.

Examples of covalent

Initial Payment covalent atoms can exist between same or opposite. Here are some types of molecules covalently links including polar, nonpolar and coordinate covalent.

o Water (H2O): In this hydrogen protons to double share electrons with unique oxygen atoms that share electrons with their own double in return. This is an example of cold covalent bonds, which are combined since electronegativity of oxygen at altitude.

or hydrogen molecule (H2): This is a non-polar covalent intermediate as a period in the same nucleus is common between the two hydrogen atoms.

O ammonium chloride (NH4Cl): This is an example of coordinate covalent distribution, where the two electrons necessary for the fixation was assigned by the same atom. This is a special box with a covalent bond.

o hydrogen chloride (HCl): This is another one for the cold covalent deposit examples where the duration of heart from some closer to the chlorine atom has an electronegativity altitude.

Here is a list of inventory of refrigerated storage and non-polar covalent examples.

Examples of polar covalent nonpolar covalent bond Examples

Hydrofluoric acid (HF), nitrogen (N2)

Ozone (O3), methane (CH4)

Ammonia (NH3), carbon dioxide (CO2)

Hydrogen sulfide (H2S), chlorine (Cl2)

They were a little scholastic examples of covalent down payment, to be when we thought at the entrance of the kind that contains alkaline bond. As mentioned earlier, the pity of electrons between atoms, which inaugurates the proton is poorly by their electro negativity special. The few-more unbalanced electro-negativity, sometimes cool, they formed molecules. More on the electro-negativity, some more electrons are shared. Almost all organic molecules composed of CO bonded covalently linked. You will find plenty of examples of covalent deposit in organic chemistry.

The chemical binds to the investigation of a large-scale operation of the molecules from simple cuts similar to the oxygen molecules of the most formidable-like DNA (deoxyribonucleic acid). Each of these molecules are held together by covalent bonding between atoms base. We hope this test has simplified the process of covalent deposit for you. Study examples of covalent lowest paid in the retail, to absorb molecular-over settings.

Thursday, July 28, 2011

Covalent and Ionic Bonds



Covalent and Ionic Bonds

There are two basic types of compounds. They are distinguished by the manner in which the atoms bind to one another in the compound. These two types are called molecular compounds and salts (or equivalently ionic compounds).

Recall, a molecule is the smallest particle of a pure chemical substance that still retains its chemical composition and properties.

Molecular Compound - These compounds are made up of molecules whose atoms bind to one another through covalent bonds.  Covalent Bond - The electrons are shared between atoms.

An ion is an atom or group of atoms that carries a positive or negative charge as a result of having lost or gained one or more electrons.  Ionic bonds occur due to the mutual attraction between atoms with positive and negative charges.

Ionic Compound - The atoms in salts are held together with ionic bonds. Unlike molecules, salts always form solids in a regular array called a crystalline solid. So, an ionic compound is a chemical compound in which ions are held together in a lattice structure by ionic bonds. To form an ionic compound, there needs to be at least one metal and one non-metal. The metal element is usually the positive charge and the non-metal element is a negative charge. Ions can be single atoms, as in common table salt sodium chloride, or more complex groups such as calcium carbonate

NaCl (Sodium chloride)
·         The chloride ion is formed when the element chlorine picks up one electron to form the anion (negatively charged ion) Cl. The salts of hydrochloric acid contain chloride ions and are also called chlorides. An example is table salt, which is sodium chloride with the chemical formula NaCl. In water, it dissolves into Na+ and Cl ions.

Molecular Formula for Molecular Compounds
As we know, molecules consist of two or more atoms bonded to one another through covalent bonds. 

The identification of these molecules is through their molecular formulas.

The Empirical Formula expresses the most simple ratio of atoms in the molecule.  For example, benzene has six carbon and six hydrogen atoms. Therefore, the ratio of carbon to hydrogen atoms is 6: 6 or simplified to 1:1. The empirical formula for benzene is CH.
Molecular Formulas express the correct ratio AND the correct number of atoms in the molecule. For benzene, the molecular formula would be C6H6.


The Structural Formula has the correct number of atoms AND illustrates the bonding structure of the molecule.


Finally, there are 3-D Structural Models and Space Filling Formula.  This is an illustration of the Space Filling Formula for benzene.




 Molecular Formula for Ionic Compounds
Ionic compounds have atoms or molecules that bond to one another through their mutual attraction between positive and negative charges.

Positively charged atoms or molecules are called cations and negatively charged atoms or molecules are called anions.

As suggested, cations and anions attract one another. Conversely, cations repel other cations, as do anions and anions.

Electrostatic attraction is indiscriminate. That is, a cation can attract more than one anion and visa versa. The result is that cation-anion attractions form a large array called an ionic compound or salt. The bonds holding these ions together are called ionic bonds.  However, this array has a very specific composition completely dictated by the charges on the cations and anions.

The composition of ionic compounds is determined by the requirement that the compounds must be electrically neutral. That is, the overall charges of the cations and anions must be zero. 
·         Na+ and Cl-   Na is +1 charge and Cl is -1 charge. Thus, one Na cation cancels one Cl anion resulting in the formula NaCl. This formula is called the formula unit since it represents only one unit of the vast NaCl array or lattice.

An ionic compounds made up of single atom is a monatomic ion

Cation
Anion
Compound
Ca2+
Cl-
CaCl2
Ba2+
O2-

K+
S2-

Fe3+
Br-

Cr3+
O2-


Molecules can also be ions - polyatomic ions. Most polyatomic ions are anions with one notable exception - the ammoniun cation (NH4+). The composition of salts with polyatomic ions is determined by the same rule as with monatomic ions.
 Cation
Anion
Compound
Ca2+
SO32-
CaSO3
Ba2+
PO42-

NH4+
S2-

Fe3+
SO32-

NH4+
CO22-

H3O+
PO43-

Li+
SO42-

NH4+
HPO42-

K+
CrO42-

Be2+
NO3-



 Teacher Copy – Answer Sheet

Ionic compounds have atoms or molecules that bond to one another through their mutual attraction between positive and negative charges:

Positively charged atoms or molecules are called cations and negatively charged atoms or molecules are called anions.

As suggested, cations and anions attract one another. Conversely, cations repel other cations, as do anions and anions.

Electrostatic attraction is indiscriminate. That is, a cation can attract more than one anion and visa versa. The result is that cation-anion attractions form a large array called an ionic compound or salt. The bonds holding these ions together are called ionic bonds.  However, this array has a very specific composition completely dictated by the charges on the cations and anions.

The composition of ionic compounds is determined by the requirement that the compounds must be electrically neutral. That is, the overall charges of the cations and anions must be zero. 
·         Na+ and Cl-   Na is +1 charge and Cl is -1 charge. Thus, one Na cation cancels one Cl anion resulting in the formula NaCl. This formula is called the formula unit since it represents only one unit of the vast NaCl array or lattice.

An ionic compounds made up of single atom is a monatomic ion

Cation
Anion
Compound
Ca2+
Cl-
CaCl2
Ba2+
O2-
BaO
K+
S2-
K2S
Fe3+
Br-
FeBr3
Cr3+
O2-
Cr2O3

Molecules can also be ions - polyatomic ions. Most polyatomic ions are anions with one notable exception - the ammoniun cation (NH4+). The composition of salts with polyatomic ions is determined by the same rule as with monatomic ions.

Cation
Anion
Compound
Ca2+
SO32-
CaSO3
Ba2+
PO42-
Ba3(PO4)2
NH4+
S2-
(NH4)2S
Fe3+
SO32-
Fe2(SO3)3
NH4+
CO22-
(NH4)2CO2
H3O+
PO43-

Li+
SO42-

NH4+
HPO42-

K+
CrO42-

Be2+
NO3-



Ionic Compounds

Ionic compounds are compounds where two or more ions are held next to each other by electrical attraction. One of the ions has a positive charge (cation) and the other has a negative charge (anion).  Cations are usually metal atoms, and anions are either nonmetals or polyatomic ions (ions with more than one atom).

What are the main properties of salts (ionic compounds)?
·         All ionic compounds form crystals.  Salts form crystals because the electrical positive and negative charges stick together in a “stack-like” formation. The arrangement is called the "unit cell". There are ten or so different general shapes.

·         Ionic compounds tend to have high melting and boiling points.  The melting point is so high that you cannot melt them with a Bunsen burner.  Why are these temperatures so high?  Recall, ionic compounds form crystals of positive and negative charges.  To break the unit cell apart requires a lot off energy. 

·         Ionic compounds are very hard and very brittle. Again, this is because of the way that they are held together.  The shape makes them hard.  Their structure does not allow them to move or bend explaining the brittleness of ionic compounds. If whacked with a hammer, the energy to break the crystal shatters it. 

·         Ionic compounds conduct electricity when they dissolve in water. If we take a salt and dissolve it in water, the water molecules pull the positive and negative ions apart.  The ions spread throughout the water.  Thinking back to electricity, it is the movement of electrons.  The positive and negative ions in the water allow electrons to flow.

Question:  Why does electricity flow effectively through salt water but not as freely through salt crystals? The ions in the solid are in a crystal structure.  The electricity does not move freely in the structure. 

Question:  Does water without salt in it conduct electricity?  Fresh water does not conduct electricity very well.  The reason you are electrocuted when you drop a hairdryer in the bathtub is because the dirt washed off the human body is ionic and the ions conduct electricity.  If you all the salt (dirt) off yourself and then drop a hairdryer in the bathtub, would you be safe?  Theoretically, yes.  In real life, you would be electrocuted because tap water has ionic compounds dissolved in it.


Wednesday, July 27, 2011

Writing Covalent and Ionic Formulas



WRITING FORMULAS & NAMING IONIC COMPOUNDS (KEY)
1.      Ammonium dichromate               (NH4)2Cr2O7
2.     Iron (II) cyanide                       Fe(CN)2
3.     Aluminum phosphite                   AlPO3
4.     Chromium (II) iodide                 CrI2
5.     Calcium bicarbonate                   Ca(HCO3)2
6.     Mercury (I) sulfite                    Hg2SO3
7.     Aluminum chlorate                     Al(ClO3)3
8.     Silver nitrate                            AgNO3
9.     Ammonium hydroxide                 NH4OH
10.    (NH4)3PO4                                 ammonium phosphate
11.    Hg2Cr2O7                                   mercury (I) dichromate
12.    PbSO3                                       lead (II) sulfite
13.    MnCl2                                        manganese (II) chloride
14.    Cr2(Cr2O7)3                                chromium (III) dichromate
15.    SnO                                          tin (II) oxide
16.    NaHSO3                                    sodium bisulfite
17.    Cu3(PO4)2                                   copper (II) phosphate
18.    FeN                                          iron (III) nitride
19.    Sr3(PO4)2                                  strontium phosphate
20.   HgNO2                                      mercury (I) nitrite



WRITING FORMULAS & NAMING COVALENT COMPOUNDS (KEY)
1.      Dinitrogen tetroxide                          N2O4
2.     Boron triflouride                               BF3
3.     Hydrogen monobromide                      HBr
4.     Dinitrogen pentoxide                         N2O5
5.     Carbon monoxide                               CO
6.     Silicon tetriodide                               SiI4
7.     Nitrogen trifluoride                           NF3
8.     Tetraphosphorous trisulfide               P4S3
9.     Dihydrogen monoxide                         H2O
10.    CaO                                                  calcium monoxide
11.    CH4                                                   carbon tetrahydride
12.    C2H6                                                 dicarbon hexahydride
13.    P4S3                                                  tetraphosphorus trisulfide
14.    As2O5                                               diarsenic pentoxide
15.    SeO2                                                 selenium dioxide
16.    SiI4                                                  silicon tetriodide
17.    CO2                                                   carbon dioxide

Tuesday, July 26, 2011

Covalent and Ionic Properties


Purpose: In this lab, you can view the properties of ionic compounds and covalent compounds. Features must be examined: the volatility, melting point, solubility in water, and electrical conductivity. You can use these properties to classify substances or analog ion.


Background: The compounds are either ionic or covalent bonds, depending on the nature of the forces that hold them together. In ionic compounds, the attraction between oppositely charged ions. This attraction is called ionic bonding. Compounds with ionic bonds in the form of crystals of a regular pattern of positive and negative ions together with electrical attraction. In covalent compounds, atoms are held together by interactions between adjacent nuclei, and the shared electrons are called covalent bonds. Covalent compounds are present in the form of discrete particles called molecules. The molecules of covalent compounds are weak forces together in groups, usually called the molecular forces. Molecules, the forces are much weaker than the strength of covalent bonds that hold together the factors within molecules or ionic bonds that maintain the positive and negative ions with crystals.

Fusion - To melt an ionic connection, it is necessary to break the ionic bonds. Therefore, ionic compounds generally have high melting points. To melt a covalent bond, there is no need to break the bonds. It is only necessary to overcome intermolecular forces much lower than hold the particles together.

Volatility - the particles of a volatile compound is held together by weaker forces, so that some people can go without a break away from our noses.

Solubility - ionic compounds tend to be soluble (or dissolved in) water, because water is a polar substance which can exert a force sufficient to overcome the ionic bond and a few ions to disintegrate. Generally, covalent compounds are less soluble in water. The tendency of compounds to dissociate or ionize in water, says a lot about how the bonds holding the connection together.

Conductivity - A way to assess the trend of the dissociation of a compound in water is to test the ability of solutions to conduct electricity. If an aqueous solution of the compound does not lead, it is called a non-electrolyte. If driving in aqueous solution, the compound is called electrolyte. The charged particles must be present and to travel freely to the effects of an electric current to flow. The amount of conduction through the solution is an indicator of ionic character of the compound. In fact, driving or not driving the solution provides an indication of the type of link on site. These different forces into account the many properties of ionic and covalent compounds such as solubility, melting point, the degree of volatility and ability to conduct an electrical current.

Procedure (Part I): 

Chemicals to be tested                                                       Materials

                                Sodium chloride                                                                   aluminum boats                                 
                                PDB                                                                                        test tubes                                              
                                Potassium chloride                                                              DI water                                                                                                                           shortening                                                                                                            hot plate  
                                                                                                                                test tube rack
                                                                                                                                stirring rod
  1. Volatility – Carefully smell each compound.  If you can detect an odor, assume that the compound has a high volatility.  Record as high or low volatility.
  2. Melting Point – Place a small amount of each substance.  Heat the sample on a hot plate and record the time it takes for it do dissolve.  The PDB will be heated on a hotplate under the fume hood.  The longer it takes the compound to melt, the higher the melting point.  Record the time it takes to melt, and whether or not it is considered to be a high or low melting point.  If the compound hasn’t melted in 3 minutes consider that the compound has a high melting point. 
  3. Solubility in Water – Put a micro-spatula of each material into a separate test tube.  Stir each with a stirring rod (rinsed between each sample) and record how likely the substance is to dissolve in water.  Record high or low solubility.
Procedure (Part II):

Chemicals to be tested                                                       Materials

                                                Sodium chloride solution                                                   spot plate
                                                Potassium chloride solution                                               conductivity testers
                                                3M HCl                                                                                 wash bottle of DI water
                                                alcohol                                                                                   berel pipettes
                                                paint thinner        
                                                salad oil
                                                sugar solution
                                                tap water
                                                distilled water
  
  1. Add one berel pipettes’ worth of each of the 9 materials listed to separate wells of a spot plate.
  2. Place the two probes into a well.  Record the results as conductive or not conductive
  3. Rinse probes w/ DI water before putting them into the next sample.  Wipe the probes with a paper towel after testing the oil and then rinse with DI water.
  4. Test each substance and record results.

Conclusion Questions: 
  1. Explain why the type of bond could determine the volatility of a substance?
  2. Does the strength of the bond have anything to do with the melting point?  Explain why.
  3. Water molecules are polar which means one side of the molecule is positively charged and the other side of the molecule is negatively charged.  Which substances tend to dissolve easier in water, ionic or covalent?   Why?
  4. What kinds of elements are in the formulas for the ionic compounds?
  5. What kinds of elements are in the formulas for the covalent compounds?
  6. Explain the difference in conductivity of tap water and distilled water.
  7. List the physical properties that indicate ionic bonding exists in a compound.
  8. List the physical properties that indicate covalent bonding exists in a compound.


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