Ionic vs Covalent Properties LAB Navaneethan Senthilraja INTRODUCTION: Throughout the Lab, several experiments will be conducted to determine the physical properties such as brittleness, conductivity, solubility, and melting points of several unknown compounds. Based on previous knowledge learned throughout the course and Grade 11 Chemistry, it is known that ionic compounds are composed of stronger bonds as it is between non-metal and metal involving a transfer of electrons, whereas covalent compounds are held by weaker bonds. PURPOSE: To classify the identity of compounds if they are ionic or covalent depending on their physical properties such as brittleness and other attributes such as solubility, melting points and conductivity. Also to recognize the differences and similarities that exist between different ionic and covalent compounds. MATERIALS: - Safety Glasses 3 Test Tubes Test Tube Rack Water - Petri Dish Unknown SAMPLES (A, B, C) Conductivity Tester Wax Paper - 3 Stoppers for Test Tubes Hotplate OBSERVATIONS TABLE Melting Point SAMPLE A SAMPLE B SAMPLE C - High Boiling Point - Very low melting point, melted nearly immediately upon contact of heat - Low Melting Point, but much slower than Sample B This study source was downloaded by 100000871024532 from CourseHero.com on 09-06-2023 10:33:05 GMT -05:00 https://www.coursehero.com/file/205878604/Lab-Ionic-and-Covalent-Properties-U1L5-OVSpdf/ Physical Appearance - Very hard and brittle, cannot be crushed - Soft not very brittle, easy to compress - Powder-like Hard and Brittle, yet seems to be softer than Sample A Solubility Soluble Nearly went solubility immediately with limited shaking Not soluble at all as powder visibly remained even after intense shaking Soluble yet it took more effort mixing to dissolve as at beginning powder remained at bottom of the test tube but only after thorough shaking did it dissolve Conductivity Is a conductor, therefore has high conductivity Low/No conductivity (as indicated by no light on conductivity tester) Low/No conductivity (as indicated by no light on conductivity tester) Ionic or Covalent IONIC COVALENT COVALENT ANALYSIS QUESTIONS: 1. Determine whether each of compounds is ionic or covalent? Based on all of the observations conducted from each of the experiments, Substance A is ionic while Substance B & Substance C is both covalent compounds. As stated in the introduction and learned throughout the course of grades 11 & 12 thus far, ionic compounds have much stronger attractive bonds making them harder to break and are considered salts, which is why they have a very high melting point and are much harder/brittle. Furthermore, since covalent compounds are made up of much weaker bonds, therefore the amount of heat energy required to destroy the bonds of a covalent compound is much weaker also causing a much softer texture and easier to compress - Solution A - Ionic - Solution A is definitely an ionic compound and hosts all the attributes of a clear ionic compound. This is because it has a high boiling point, requires a lot of heat energy to destroy bonds, is very hard/brittle, was also soluble which most ionic compounds are, and finally has high This study source was downloaded by 100000871024532 from CourseHero.com on 09-06-2023 10:33:05 GMT -05:00 https://www.coursehero.com/file/205878604/Lab-Ionic-and-Covalent-Properties-U1L5-OVSpdf/ conductivity which is a common attribute amongst most ionic compounds. - Solution B - Covalent - Solution B portrays all the attributes of a covalent compound such as a very low melting point (melted nearly immediately), soft physical structure, insoluble in water, and very weak to no conductivity. This is a clear case of a covalent as there are no exceptions and follows all the rules exactly - Solution C - Covalent - Solution C is a little different than A and B as it does not completely exhibit the physical properties of an ionic or covalent compound although it exhibits a mixture of both, which indicates that solution C has an electronegativity difference near both covalent and ionic which is causing a variety of results. Although based on careful deduction of all experiments, Solution C is a covalent compound, as it was not conductible at all as indicated by the conductivity meter meaning it must be covalent. Also, it has a low melting point and melted within 3 minutes, and even though it was hard, based on the video it was less hard and brittle than substance A which was ionic. Finally even though at the end it was soluble it took a while as at first, the powder condensed at bottom of the test tube and only after extreme shaking was it able to fully dissolve. As displayed from observations even though it has attributes of both types of compounds, it leans more toward a covalent compound as it has weak to no conductivity as tested in the conductivity meter, therefore it is classified as a covalent compound. 2. Any Patterns that you have observed in the property of solubility? After conducting the solubility experiments on the three different substances, it is clearly seen that an ionic compound such as Substance A, completely dissolved in water nearly instantaneously while a covalent compound such as Substance B did not dissolve and simply condensed at bottom of the test tube. Although this is the case, it will not always work like this as some compounds exhibit both properties as the difference in EN is close to both covalent and ionic compounds such as Substance C. Through full lab analysis Substance C was deciphered to be a covalent compound however it still dissolved in water even though it took intense shaking measures to fully dissolve signifying it has a diff of EN that is close to an ionic compound which is why it exhibits some of an ionic compounds attributes slightly. This study source was downloaded by 100000871024532 from CourseHero.com on 09-06-2023 10:33:05 GMT -05:00 https://www.coursehero.com/file/205878604/Lab-Ionic-and-Covalent-Properties-U1L5-OVSpdf/ 3. What can you say about the other properties: melting point and electrical conductivity in relation to the ionic or covalent character of compounds? In terms of the other properties, there is a clear pattern that follows between the covalent and ionic compounds. Ionic compounds have a higher melting point compared to those of covalent compounds which have much lower melting points. This makes sense with our logic since ionic bonds are much stronger involving a transfer of electrons, it requires much more heat energy to break the bonds compared to those of a covalent bond. On the other hand, ionic compounds are the only compounds to be conductors as they form ions in contact with water causing them to be a strong conductor. In contrast to covalent compounds that do not break apart into ions in water causing no conductivity at all which is why it was deducted that substance C is not ionic compound as it would’ve formed ions and been conductive if it was an ionic compound. 4. Predict the Following a. Solubility of Sodium Iodide in Water Since sodium iodide is an ionic compound therefore as discussed throughout the lab, it will break apart and dissolve in water therefore making it soluble. b. Melting Point of Sodium Iodide As sodium iodide is an ionic compound involve a bond between metal and non-metal using a transfer of electrons therefore the bonds holding the compound are very strong causing the melting point to be much higher as a strong amount of heat energy is required to destroy the bonds of the ionic compound, sodium iodide. c. Electrical Conductivity of a glucose solution Glucose is an example of covalent compound therefore meaning that it will not dissociate into ions upon contact of water therefore causing glucose to have no conductivity and be a poor conductor of electricity. This study source was downloaded by 100000871024532 from CourseHero.com on 09-06-2023 10:33:05 GMT -05:00 https://www.coursehero.com/file/205878604/Lab-Ionic-and-Covalent-Properties-U1L5-OVSpdf/ Powered by TCPDF (www.tcpdf.org)
