CHAPTER 2 LITERATURE REVIEW 2.1 Layered Double Hydroxide Layered double hydroxide (LDH) is an inorganic anionic material that is formed by two or more types of metallic cations and posses the positively charged layers and exchangeable anions. LDH can be named as anionic clays by the comparison with the cationic clays that contains the cation in the interlamellar region. In LDH, the species that constitutes the interlayers is the anion. Tracing back the historical background of LDH : (Rives, 2001) The structure of LDH is derived from parent structure of brucite, Mg(OH2) by isomorphous substitution of divalent cations. Brucite consists of a hexagonal close packing of hydroxy ions with the alternating layers of octahedral sites occupied by divalent cations. The Mg2+ metal cation is then substituted by the trivalent cation like Al3+ and thus creating the a net positive charge hydroxide basal layer. The charge density M3+/(M2++M3+) is proportional to the ratio of the trivalent metal and the formation of pure LDH usually takes place for stoichiometries range of 0.20 < x < 0.33. This charges are electrically balanced by the intercalation of anions species into the interlayer region while the water molecules resides the remaining space. These M2+/M3+ (OH)6 octahedral unit shares edge and leads to the formation of the two-dimensional infinite sheets. These sheets may stacked on top of each other and connected by hydrogen bonding between the hydroxyl groups of adjacent sheet (Cavani et al.,1991; Rives, 2001). Figure Schematic Representation of hydroxide layers in the hydrotalcite (Palmer et ... ... middle of paper ... ... the choice of the guest species can be based on the resulting properties of desired product (Ozin, 1992). Therefore, a diversity of multifunctional composite with nanosize range materials can be created by highly tunable interlamellar composition coupled to the choice of organic moiety (Leroux& Besse,2001). There are several pathway for the incorporation of guest material into the nanohybrid such as exchange, coprecipitation, hydrothermal treatment, in-situ polymerization, surface-mediated insertion, restacking or reconstruction techniques (Leroux& Besse,2001). In this study, the host and the guest anions are included in the mother liquor and followed by the aging process to yield the formation of the well-ordered nanolayered structure by spontaneous self-assembly or coprecipitation (Messersmith et al., 1995; Hussein et al., 2005). 2.5 Controlled Release
When in solution, the hydronium and chloride ions formed will be partially surrounded by water molecules via ion-dipole bonds, an electrostatic force of attraction that exists between charges in the ions and the partial charges in the water molecules. Water molecules surrounding ions is called hydration.
We thank the University of Oklahoma and the chemistry faculty for providing the space, instructions, and equipment for the development of this report and experiment.
2-butoxyethanol, a colorless liquid with a mild odor, is used in different paints, primers, and kinds of ink, along with numerous household cleaning products commonly found, to remove substances such as grease and oils. However, the usage of 2-butoxyethanol comes with risks as well. 2-butoxyethanol’s risks outweigh the rewards of it being used.
The major sites for the production of ammonia are the intestines, liver, and kidneys. It is biosynthesized through normal amino acid metabolism. The kidneys generate ammonia from glutamine by the actions of renal glutaminase and glutamate dehydrogenase. Ammonia is formed from urea by the action of bacterial urease in the lumen of the intestine, which is absorbed from the intestine by the portal vein. Amines obtained from diet and monoamines that serve as neurotransmitters or hormones can create ammonia by action of amine oxidase. In purine and pyrimidine catabolism, amino groups attached to the rings are released as ammonia.
The oxide of aluminum is amphoteric—showing both acidic and basic properties. The most important compounds include the oxide, hydroxide, sulfate, and mixed sulfate compounds. Anhydrous aluminum chloride is important in the oil and synthetic-chemical industries. Many gemstones—ruby and sapphire, for example—consist mainly of crystalline aluminum oxide.
An acid is a substance that produces hydrogen ions, H+ or hydrodium ionsH3O+ in solution. There are three “kinds of acids”: Arrhenius, BrØnsted-Lowry, and Lewis Acid. An Arrhenius acid is a substance the increases the concentration of hydrogen ion, H+ or hydronium ions H3O+when dissolved in water. You must have water. A BrØnsted-Lowry acid is any substance that donates a hydrogen ion, H+ to another substance. A Lewis acid is any substance that accepts a lone pair of electrons.A strong acid is one that breaks apart close to 100% when in solution (example HCl). When dissolved in water, HCl breaks apart into H+ and Cl- ions. Not all acids break apart. A weak acid is/are chemicals that do not break apart well. Acids have a sour taste, they are: corrosive and electrolytes. Acids react with active metals (group 1 or 2) to produce hydrogen gas, H2 They also react with bases to produce salt and water (a neutralization reaction). An Arrhenius base is any substance that increases the concentration of hydroxide ions (OH-) when dissolved in water. A BrØnsted-Lowry base is one that accepts a hydrogen ion, H+. A Lewis base is any substance that donates a lone pair of electrons. Bases have a bitter taste, bases react with acids to produce a neutralization reaction, and solutions that are basic feel slippery. On the pH scale, 7 is neutral. An acidic solution will have a greater hydrogen ion than hydroxide ion concent...
In this lab, I determined the amount of heat exchanged in four different chemical reactions only using two different compounds and water. The two compounds used were Magnesium Hydroxide and Citric Acid. Both compounds were in there solid states in powder form. Magnesium Hydroxide was mixed with water and the change in heat was measured using a thermometer. The next reaction combined citric acid and magnesium hydroxide in water. The change in heat was measured as well. For the third reaction citric acid was placed in water to measure the change in heat. In the last reaction, citric acid was combined with water. The heat exchanged was again measured. It is obvious we were studying the calorimetry of each reaction. We used a calorimeter
In our experiment we utilized the hydrate cobaltous chloride. Hydrates are crystalline compounds in which one or more molecules of water are combined with each unit of a salt. Cobalt (II) chloride hexahydrate is an inorganic compound which is a deep rose color in its hydrated form. As an inducer of
When a miscible salt is completely dissolved in liquid solvent to dissociate positive and negative charged ions, then this mixture is called liquid electrolyte.
Dofasco uses hydrochloric acid to remove scale, oxides and other impurities that form on the surface of hot-rolled steel coils in a finishing process-a pickling line. Hot-rolled iron moves through baths of hydrochloric acid to remove impurities that form on the surface of the steel during the manufacturing process. The acid is used as a substance to create a clean-surfaced product. Hydrochloric acid is a clear, colorless, solution with a strong odour made of hydrogen chloride ions and water. This acid is highly corrosive and is used for many industrial purposes such as the pickling process. It is highly reactive, which is why it works efficiently to remove impurities off the surface of steel when it reacts with the steel. During the hot rolling of the
Plontke, R. (2003, March 13). Chemnitz UT. TU Chemnitz: - Technische Universität Chemnitz. Retrieved April 1, 2014, from http://www.tu-chemnitz.de/en/
The ph scale can be used to determine how strong an acid is. One meaning the acid is very strong and six meaning the acid is very weak. Some examples of acids are in the table below
Ionic compounds, when in the solid state, can be described as ionic lattices whose shapes are dictated by the need to place oppositely charged ions close to each other and similarly charged ions as far apart as possible. Though there is some structural diversity in ionic compounds, covalent compounds present us with a world of structural possibilities. From simple linear molecules like H2 to complex chains of atoms like butane (CH3CH2CH2CH3), covalent molecules can take on many shapes. To help decide which shape a polyatomic molecule might prefer we will use Valence Shell Electron Pair Repulsion theory (VSEPR). VSEPR states that electrons like to stay as far away from one another as possible to provide the lowest energy (i.e. most stable) structure for any bonding arrangement. In this way, VSEPR is a powerful tool for predicting the geometries of covalent molecules.
In my experiment I am testing which vegetable and pickling solution will increase the acidity in the solution most and have the most chemical change. To figure this out you need to consider some important factors. These factors are how acidity changes, chemical changes, and how acidity is measured. These factors really impact how we would measure and see the results.
For centuries, many scientists and researchers have pondered on the idea of combining two or more substances together to create something new. These explorations have led to the idea of what kind of reactions would occur when diverse elements are combined. This is a concept known as chemistry, a part of science that corresponds with how matter is created from different properties and the process it goes through to create a new substance. Chemistry is a scientific concept that is used in everyday life and is a crucial part in the development of new technology and substances that allow today’s quality of life. The use of chemistry branches off into many different routes, including medical related fields, agriculture, and even in weapons of