Why Some Polar Covalent Substances Are Soluble In Water

Water (H2O) is a good solvent because it is partially polarized. The hydrogen ends of the water molecule have a partial positive charge, and the oxygen end of the molecule has a partial negative charge. This is because the oxygen atom holds on more tightly to the electrons it shares with the hydrogen atoms. The partial charges make it possible for water molecules to arrange themselves around charged atoms (ions) in solution, like the sodium (Na+) and chloride (Cl−) ions that dissociate when table salt dissolves in water.

The product obtained had a melting point of approximately 107 °C and a weight of .324 grams. Some of the product would not dissolve in water and so was removed through vacuum filtration, which left .141 g not dissolved in solution. It took 13.2 mL of sodium hydroxide to turn the solution of the product dissolved in water pink. A molecular weight of 138.63 g/mol was calculated from the data. These results indicate that the product was 2-methylbenzoic acid, the Grignard reagent was 2-methylphenylmagnesium bromide, and the unknown bromide solution was 2-methylbromobenzene. Calculations showed that the limiting reagent of the Grignard preparation was magnesium and that the experiment had a 23.13 % yield.

6. The solubility of the solids were tested using a micro tray, by placing them in water and oil to observe their polarity,

Substance A and B were weighed; Substance A weighed 0.502 g and substance B weighed 0.503 g. Both substances were put into two different test tube with approximately 8 ml of DI water into the test tub. Substance A and B were stirred and B dissolved while A did not. This shows that B is soluble in water compared to A. Thus, shows that B is soluble in water than A. The reason why B is soluble in water is because it has a higher dipole moment than A. With a higher dipole moment, it shows that it is soluble in water since it is polar and the bonds were easily broken.

Ionic compounds are soluble in water to a certain point depending on the compound. The level of solubility changes among different compounds. Some ionic compounds can completely dissolve in water and appear to be a homogeneous mixture. Although, some ionic compounds dissolve very little, and could be considered insoluble, since it does not dissolve fully. Depending on the compound, the level of solubility can be high or low. However, ionic compounds could dissolve to a certain degree. If the solution appears to be a heterogeneous mixture, many may assume through visual representation that it may be insoluble. As stated previously, the smallest amount of solubility should be considered. To confirm whether or not the substance is soluble, observe the efficiency when conducting electricity. Due to practical reasons, the slightest solubility could be considered insoluble by people.

The unknown ionic compound was composed of translucent crystals. It had no odor, was soluble in water, and its electrical conductivity in water was measured at 1.66V, as indicated in Table 1. The compound burned a bright red during the flame test consistent with the flame signature of calcium, as indicated in Table 2, and along with the fact that the compound was soluble in water, this helped us to eliminate the possible presence of the poorly soluble salts (Cooper, 2008). However, tests for these anions were still performed.

While the data did not show no conduction, it had shown low conduction. Unknown 2 also had the lowest melting point. This is supported because non polar covalent bonds have the lowest melting point out of the tested bonds because there is not an atom pulling electrons closer because they have the same electronegativity. Also non polar covalent molecules will only dissolve in other non polar covalent molecules, and Unknown 2 dissolved in cyclohexane, which is a non polar covalent bond. Unknown 3 was classified as ionic bond based off data.

As a result of this lab experiment, the hypothesis is attested to be precise as the ionic compounds did go through a double displacement reaction. The purpose of this experiment was to establish what occurs when two pairs of compounds react with one another. The information collected while doing the lab has allowed more knowledge to be obtained, as one can visibly see the changes happening and different signs of chemical changes. The cations and anions in the ionic compounds have successfully exchanged places with one another, creating the compounds with the different properties evident in the observation given. For example, precipitates were visible in almost all reactions in this experiment. Therefore, this lab experiment was held to demonstrate

The purpose of this lab was to explore the characteristics of hydrates. Hydrates are solid ionic compounds that contain water that is chemically bound to the crystal. In doing this lab, the percentage of water contained in various hydrates, if dehydration is a reversible or irreversible change, and the mathematical relationship between starting mass and mass lost. As there is no simple way to predict the amount of water molecules in a hydrated compound, it must be determined by experimenting. This experiment involves heating said hydrates so the water molecules evaporated from the solid compound. In the different

Because sodium chloride is made up of ions, it is called an ionic substance. In the video " Hands-On Science with Squishy Circuits " she shows us how play-doh made with salt and play-doh made with sugar can conduct energy. If you break the salt play-doh into two pieces then put on led light on each side it will turn on, but when you push them back together it turns off. If you put a piece of the sugar play-doh in between the salt play-don and then connect the led light it will turn on again.

Solubility – Very soluble (water), Freely soluble (methylene chloride, chloroform, alcohol), Slightly soluble (acetone) and Insoluble (ether).6 Melting point - 120°C or 248°F.5

#3 is an ionic compound, we think its name is Sodium Carbonate. #3 had a high melting point, was able to dissolve in water, produced no light and 0 bubbles demonstrating no conductivity. However, three other datas showed that it produced more than 500 bubbles which lead to a belief that my data may not be correct; so Sodium Carbonate does have conductivity. #3 melted 20 times slower than #4 which was molecular compound. These evidences matched the criteria used to identify an ionic compound. Ionic compound consists of metal and nonmetal; the structure of Sodium Carbonate shows Na as a metal and O as nonmetal. Na contain positive charges while O contain negative charges because of stealing electrons from Na to O. Both opposite charges are attracted

On the other hand, covalent compounds may take the form of either solid, liquid, or gas; moreover, they are loose and molecular. Once the ions are dissolved, the presence of charged particles distributed throughout the liquid allows the solution to conduct electricity. Therefore, ionic compounds have higher melting and boiling points compared to covalent compounds. Similarly, ionic compounds dissolved in water make an electrically conductive solution, which are able to move freely through the solution carrying the charge and conducts an electric current. Correspondingly, covalent compounds do not exhibit any electrical conductivity in either pure form or when it is dissolved in water.

As mentioned in the discussion, olive oil, vegetable oil, crisco, and lard were soluble in nonpolar solvents and insoluble in polar solvents. This is due to the chemical composition of polar and nonpolar substances which results from the molecular shape as well as properties of dissolving solutes in solution. Polar substances are hydrophilic and contain polar Van Der Waals interactions (intermolecular forces) such as dipole-dipole forces, ion-dipole forces, and hydrogen bonding. Nonpolar substances are hydrophobic and contain non-polar Van Der Waals interactions. ‘Like dissolve like’ is the reason only polar solutes dissolve in polar solvents and why nonpolar solutes dissolve in nonpolar solvents. Molecules with similar polarity have similar intermolecular forces and therefore, can interact with each, or in this case dissolve9. Additionally, the solubility of a compound is determined by the length of the hydrocarbon chain. Long hydrocarbon chains such as the one found in oleic acid makes a compound more insoluble10. Therefore, since the lipids used in this experiment were hydrophobic substances and each lipid has long hydrocarbon chains, the results were consistent with the scientific literature and principles.

The objectives of this lab are, as follows; to understand what occurs at the molecular level when a substance melts; to understand the primary purpose of melting point data; to demonstrate the technique for obtaining the melting point of an organic substance; and to explain the effect of impurities on the melting point of a substance. Through the experimentation of three substances, tetracosane, 1-tetradecanol and a mixture of the two, observations can be made in reference to melting point concerning polarity, molecular weight and purity of the substance. When comparing the two substances, it is evident that heavy molecule weight of tetracosane allowed