What Is the Difference between an Ionic and a Covalent Bond - Essay Example

Running head: CHEMISTY CHEMISTY Goes Here al Affiliation Goes Her The paper answers three questions related to chemistry. The questions include topics such as ionic and a covalent bonds, ionic compounds, covalent compounds and polymers. Thus the answers give a clearer picture of the topics related to chemistry. Chemistry 1. What is the difference between an ionic and a covalent bond? How is each formed? A compound or a molecule is formed when two or more than two atoms are linked together by means of chemical bonds. These chemical bonds are of two main types, namely covalent bonds and ionic bonds. According to Kind (2003), in the formation of a covalent bond, the atoms are linked together by means of electron sharing. Further, a covalent bond can be of two types, that is a non-polar covalent bond and a polar covalent bond. When the bonded together atoms share the electron equally between them, the bond thus formed is known as a non polar covalent bond. As against this, if the electron sharing is not equal and one of the atoms attracts the electron more towards itself, then such a bond is known as a polar covalent bond. On the other hand, in the formation of an ionic bond, the linking together of atoms happens by means of attraction between ions which are oppositely charged. However, there may be some variations in the number of electrons that are exchanged in this process. Formation and Difference between Ionic and Covalent Bonds When it comes to the ionic bond formation, there is complete transfer of electrons from one bonding atom to another. According to Kind (2003), the ions bearing opposite charges are made to get attracted to each other through electrostatic forces. For example, when sodium chloride is formed by means of ionic bonding, the only electron of sodium which bears a positive charge is lost to the ion of chlorine which has a negative charge on it. This process results in an increase in size of the atom which gains electrons and shrinking of the atom which loses electrons. On the other hand, in case of covalent bond formation, ions are equally shared between the atoms. Covalent bonds can take place only between atoms having similar ability to lose and gain ions. These bonds are formed between two non-metals bearing the same level of electromagnetism. None of the atoms has the ability or strength to pull electrons from the other. Hence, the covalent compounds stabilize by sharing electrons from the outer molecular orbit, like methane. The ionic bonds have a high polarity but they do not have any definite shape. Both the melting and boiling points for an ionic bond are quite high. Kind (2003) states that the ionic compounds are solid at room temperature but cannot conduct electricity in this state. However, these compounds do possess the ability to conduct electricity in their molten state. On the other hand, the covalent bonds have a low polarity but they have a definite shape. The melting point and boiling point for a covalent bond is relatively lower. At room temperature, the covalent compounds are found to be in a liquid or gaseous state. 2. Explain why ionic compounds dissolve more easily in water than covalent compounds. Include a specific example of each type of compound and the result when each is placed in water In case of Ionic compounds (also known as salts), when these are placed in water (an aqueous medium), there begins to take place a tug-of-war between the ions in the salt and the polar water molecules with the water molecules forming a cage around the solvated ions. These tug-of-war forces are electrostatic in nature and operate between water-ion attractions as well as ion-ion attractions. According to Barker (2001), if the electrostatic force in case of water-ion attraction is stronger, then the salt is soluble in water. On the other hand, if the electrostatic force in the case of ion-ion attraction is more, then the salt is insoluble. For example, when sodium chloride (NaCl) is placed in water, it dissolves completely and dissociates to release sodium and chloride ions. Similarly, all nitrates, chlorides (except those of silver, mercury and lead) and most of the sulfates (except those of barium, lead and strontium) are soluble in water. On the other hand, the non-polar compounds (covalent compounds) interact with each other by means of dispersion forces. Barker (2001) states that the dispersion forces are quite weak and results from temporary dipole formation in non-polar compounds. In case of iodine solids (covalent compound), the two iodine molecules are held together by means of these weak attractive forces. Water has a combination of different forces operating between its molecules like dispersion forces, strong hydrogen bonding forces and strong dipole-dipole forces. All these forces acting together keep the water molecules strongly attracted to each other. As a result of this, the iodine molecules (or any other non-polar compound) cannot break them apart. This is the reason that covalent compounds are only slightly soluble in water. 3. Describe polymers, and how they are formed. What are the benefits of polymers? Provide an example of a naturally occurring polymer and a man-made polymer and the properties of each. Loeffler (1989) defines polymers as macromolecules which are made up of structural units which are repetitive. These composing units are connected to each other by means of covalent bonds. Although, polymer is a term which is synonymously used with plastics, this category includes a wide variety of compounds (both synthetic as well as natural), having differing properties. Polymers are formed by means of a process known as polymerization which involved the bonding of many small molecules called monomers through covalent bonds. During this process, each monomer may lose some chemical groups. The distinct part of a monomer which gets incorporated in the macromolecule is called a repeat unit. According to Loeffler (1989), polymers can be formed through laboratory synthesis, biological synthesis or by modifying natural polymers. Since, polymeric substances exhibit a wide range of properties; these play an essential role in everyday life. The role of polymers may range from widely used synthetic plastics to naturally occurring biopolymers like proteins which are necessary to sustain life. Since ages, man has been using natural polymers like amber, shellac, rubber and cellulose (which are the main ingredient of paper and wood). The list of synthetic polymers which form a part and parcel of our industries include bakelite, PVC, polyethylene, nylon, synthetic rubber, neoprene and so on. These are even used as study material in fields like polymer physics, polymer chemistry and polymer science. Polymers may be natural or synthetic. One of the most important natural polymers is the naturally occurring rubber which is obtained from the latex of several trees. The natural rubber is quite sticky and hence difficult to handle. Also, it has very low elasticity and durability. Usually, the natural rubber is processed chemically and converted into synthetic rubber which has better physical, chemical and mechanical properties. On the other hand, one of the widely used synthetic polymers is polyethylene. It forms the backbone of the industrial sector. It can be easily molded and cast into a wide variety of shapes and sizes. Due to its low cost of production, it is often used in construction. Polyethylene is strong, hard, stiff and dimensionally stable. It has low water absorption, good chemical resistance against oils and grease, good self extinguishing properties and can act as a good gas barrier. Usually, it is colorless and highly transparent. References Barker, V. (2001) Chemical Concepts: Introducing Chemical Reactions, Education in Chemistry 38 (6): 147 Kind, V. (2003) Chemical Concepts: Chemical Bonds Education in Chemistry 40 (4): 93 Loeffler P.A. (1989) Fundamental Concepts In The Teaching Of Chemistry, Journal of Chemical Education 66 (11) 928 – 930 References Baez, B.( 2000) “Agency, Structure, and Power: An Inquiry into Racism and Resistance for Education.” Studies in Philosophy and Education 19, no. 4: 329-348 Levine, Alan J. (1996) “Race-Structured Thinking Today, Race Relations Within Western Expansion”, Connecticut: Praeger. Smaje, C.( 2000) “Structure.” In Natural Hierarchies: The Historical Sociology of Race and Caste, Massachusetts: Blackwell Publishers, Read More