Which type of compound usually has higher melting points: ionic compounds or covalent compounds? What is the reason for this difference in melting points? (3 points) - Ionic compounds have higher melting and boiling points than covalent compounds. The electrostatic attraction in an ionic bond is very strong hence a lot of heat energy is required to break it down, ionic bonds have high melting and boiling points. However, in covalent bonds, the intermolecular forces are very weak and easily broken, hence lesser heat is required and thus covalent bonds have lower melting and boiling points.
03.06 Covalent Bonding and Lewis Structures: Pre-Lab and Rubric Before You Begin: You may either copy and paste this document into a word processing program of your choice or print this page. Research the answers to the following questions on the internet and write your answers in your own words. For each answer, include the address of the web site (or title and author of a book or article) that you used to help you answer the question. 1. Which type of compound usually has higher melting points: ionic compounds or covalent compounds?
Ethan D. Wilhelm September 10, 2012 Chemistry 121 section 8 Friday 9-12 Sarah Gains Unknown Substance Lab Purpose: The purpose of this lab was to identify an unknown substance B by finding enough of its physical properties that we could eliminate all substances it can’t be. We use micro lab to help us find the boiling point, freezing point and mass. Then we tested the solubility of the unknown substance in water, hexane, and Alcohol. With this information we were able to find the identity of the unknown substance B. Procedure: Throughout this lab we were finding the physical properties of substance B.
While hydrogen bonds have a uniquely high surface tension, van der Waals forces have a relatively weak attraction, which causes low surface tension. According to an author of Chem Guide, Jim Clark, in van der Waals forces, “the electrons are mobile, and at any one instant they might find themselves towards one end of the molecule, making that end slightly positive” (2000). In other words, oil is NOT a polar molecule like water, which causes the molecules to not stick to each other as well. The reason tension would occur is because the
Which type of intermolecular attraction (dispersion force, or hydrogen bond) exists in each of the following liquids? hydrogen bond hydrogen bond dispersion force hydrogen bond Predict which liquid in each pair has the higher boiling point. CH3COOH C2H5OH If the molecules in a liquid are weakly attracted, which of the following properties has a high value? vapor pressure (high when attraction is low) boiling point is low (it is only high when molecules are strongly attracted) viscosity is low (it is only high when molecules are strongly attracted) surface tension is low (it is only high when molecules are strongly attracted) Distinguish between a solid and a liquid at the molecular level. Solids and liquids differ at
Experiment#2 “Separating the Components of a Ternary Mixture” By Mohammad Bazargan Lab partners: Aaron Radtke, Kevin Campbell, Austin Gilchrist Instructor: Professor Mundell Section #: 12 Sep/14/2011 Abstract In this laboratory, we used physical and chemical properties to separate the components of a ternary (three substances) mixture. We also determine the percentage of each substance in the mixture. The percentages are the following,38.2% NaCl, 40.45% SiO2, and 72.84% CaCO3.The mentioned substances were all separated using methods such as filtration, evaporation and reaction with other chemicals which will be explained throughout this report. Intro Mixtures are \ physical combinations of two or more substances where each substance keeps its own chemical identity. Mixtures can be classified as either homogeneous or heterogeneous.
Even though the results under hexane and toluene are similar, the distances of original mixture, first and second fraction are different from hexane and toluene solvent because they have different polarity. As first fraction containing fluorene, which is much non-polar than fluoreone, fluorene in first fraction is much easier to carry by the moving non-polar solvent. Thurs, as the more non-polar the solvent is the longer distance that fluorene will move. Since hexane has larger non-polar carbon-hydrogen single bond groups than toluene, it is much non-polar than toluene. As the result of this, it can explain why the distance of fluorine in hexane is longer (1.3 cm) than the one in toluene (0.5 cm) and due to less non polar toluene has.
Assignment 03.06 Covalent Bonding and Lewis Structures Part I: Lab Ciara f Insert completed data tables for each part of the lab. Be sure that the data tables are organized and include units when necessary. Melting Point (4 points) |Substance |Melting Point | |Substance A |Higher than 300 C | |Substance B |210 C | |Substance C |Higher than 300 C | |Substance D |130 C | Conductivity (4 points) Part II |Substance A |Conductive |Substance C |Conductive | |Solid |No |Solid |No | |Liquid |Yes |Liquid |Yes | |Aqueous |Yes |Aqueous |Yes | |Substance B |Conductive |Substance D |Conductive | |Solid |No |Solid
Viscosity can be affected by three main factors, Firstly, the higher the temperature, the lower the density of the magma, causing it to flow more easily. Secondly, the greater the amount of dissolved gases in the magma, the less viscous it will be, and lastly the higher the silica content, the more viscous it will be. Thicker, more viscous magma has a greater potential for explosive eruptions and therefore represent the greatest potential hazards. The thickest type of magma is known as Acidic Magma. Its relatively low temperature, high silica content and leads to blockages and powerful eruptions.
(Nitrogen, hydrogen, oxygen, carbon dioxide, and other elements cause weld defects if introduced to the weld pool.) After a while it was discovered that argon has some advantages over helium. Because argon is heavier than helium, less flow rate is needed. The lower flow rate requirement makes argon better for flat welding. Helium is good for overhead, because it is lighter and thus flows upward.