The mixed alkali effect in the glass materials has been the subject of study in the recent years. Many properties of glasses show non linear behaviour of exhibiting a minimum or maximum, as a function of alkali content, if one of the alkali ions is gradually replaced by another alkali keeping total alkali content constant. This behaviour is called mixed alkali effect. The general formula for mixed alkali oxide glass is y[x.A2O + (1-x) B2O] + (1-y) glass former, where A and B are alkalis. The extent of departure from linearity, the direction of variation (positive or negative) depends on the property examined and the glass system. The behavior of mixed alkali effect is independent of glass forming oxides. It is being observed in silicates, borates, phosphates, germanates, tellurites, boro alluminate, alumino silicates, borotellurate etc., glasses. It is also observed that properties related to cationic movement are more sensitive to mixed alkali effect [1-3]. Alkali oxy borate …show more content…
Further, among different manganese ions, Mn2+ and Mn3+ are well known paramagnetic ions and Mn2+ and Mn4+ are identified as luminescence activators [14]. Further, it is also quite likely for manganese ions to have link with borate groups; strengthen its structure and may raise the chemical resistance of the glass. The content of manganese in different forms in different valence states exist in the glass depends on the quantitative properties of modifiers and glass formers, size of the ions in the glass structure, their field strength, mobility of the modifier cation etc. Hence, the connection between the state and the position of the manganese ion and the physical properties of the glass is expected to be highly
Alka-Seltzer is made up of baking soda, aspirin, and citric acid which gives the tablet the fizz when dropped in any temperature water. “Alka-Seltzer is a medication that works as a pain reliever and an antacid. (Antacids help neutralize stomach acidity, which can cause heartburn.)” (Science Buddies, Carbonation Countdown: The Effect of Temperature on Reaction Time). To take the Alka-Seltzer tablet you have to dissolve it in water causing a chemical reaction to form and the whole solution begins to fizz. The fizz occurs since when you drop the tablet in the water the baking soda and the citric acid react causing the water to fizz also “sodium bicarbonate splits apart to form sodium and bicarbonate ions” (Science Buddies, Carbonation Countdown: The Effect of Temperature on Reaction Time). When the Alka-Seltzer is dropped in the water then a chemical reaction forms allowing the Alka-Seltzer to dissolve. Temperature is related to this experiment because the temperature affects how fast the hydrogen ions react with the bicarbonate ions and as the temperature increases the movement of the molecules increases in speed and vice versa (Science Buddies, Carbonation Countdown: The Effect of Temperature on Reaction Time).
Hypothesis: The Alka Seltzer will dissolve fastest in hot water and slowest in cold water.
Mixed melting point was used to confirm the identity of the product. The smaller the range, the more pure the substance. When the two substances are mixed; the melting point should be the same melting range as the as the melting range obtained after filtering. If the mixed melting point is lower one taken from the crystals, then the two substances are different.
The ability to analyze a substance and determine properties of the substance is an important skill for AP Chemistry students. Major concepts for the “Analysis of Alum” laboratory are percent composition, water of hydration, and molecular formula. They will be used in three different experiments to determine the melting point of alum, the mole ratio of hydrated water to anhydrous alum, and percent of sulfate ion contained in alum. The values acquired in the lab should be close to the calculated values of 92.5 ˚F, 12 moles of water to 1 mole of alum, and 59%, respectively.
American businesswoman Carly Fiorina once concluded, “If a decision-making process is flawed and dysfunctional, decisions will go awry.” In the critically acclaimed memoir The Glass Castle, Jeannette Walls pilots a turbulent excursion through the bottleneck of her childhood and dysfunctionality and flawed decision-making is all too common. Throughout this memoir the reader learns of the the appearances and disappearances of stability and functionality, discovers the theme of fantasy vs. reality, and determines how and why the familial dynamics of the Walls alter through the duration of the memoir. The reasons for the instability of the family are evident.
To obtain a detailed knowledge on the effect of Sensitization on the hardness of the samples, two kinds of hardness determination tests were performed.
GLASS written by ellen hopkins intermenes the real life struggles that teenagers face everyday, from love to drugs to destructive relationships. Ellen really hits home showing the life of a once 4.0 honors student Kristina; whose life easily got turned upside down from one toxic summer at her fathers that will show the darkest side possible of life. An estimated 12 percent of children in the United States live with a parent who is dependent on or abuses alcohol or other drugs. Based on data from 2002 through 2007, it was to be reported that 8.3 million children under the age of 18 lived with at least one substance-dependent or substance-abusing parent according to Substance Abuse and Mental Health Services Administration (Paragraph 4). The bond between a child and their parents is so pure yet
Osmosis Experiment Planning Aim: The main subject that I will be planning to investigate is the effects of a concentrated sucrose solution on potato cells on the basis of the Osmosis theory. Background knowledge: The plant cell and its structure To understand osmosis in detail I will need to explain the plant cell (which is the cell included in the osmosis experiment) and its cell membrane. Below I have a diagram of a plant cell: [IMAGE] Osmosis is about the movement of particles from a higher concentrated solution to a lower concentrated solution to create an ethical balance via a partially or semi permeable cell membrane. Osmosis in simple terms is the exchange of particles between the cytoplasm inside the cell and the solution outside the cell. What makes this exhange is the partially permable cell membrane.
In order to understand the obsidian hydration dating method, a model that can demonstrate the process of glass hydration under a certain range of environmental conditions is needed. To implement this, the nature of the concerned materials i.e. glass and water should be adequately known so that the interaction between them can be predicted on the basis of the properties of each substance (Stevenson et al. 1998). There is no consensus among archaeologists and geochemists on how best to model hydration rates. They have long debated on how hydration-rind thickness could tell us about time. The confusion seems to be based on two points. First, after hydration begins, water is no longer reacting with the pure glass. Rather it reacts with an already hydrated layer. The classic diffusion model breaks down at this point. Second, the different variables that determine the hydration rate are mutually interacting. Several researchers have observed a shift from classic diffusion between hydration-rind thickness and time to a linear relation, based on changes in pH. In turn, pH, in a closed system, is influenced by how long the hydration has occurred (Tremaine 1989). As alkali ions leach into solution and are replaced by hydrogen or hydronium ions, the pH of the solution will increase (Bra...
Ever think you are in control only to find out that you are not and you are in way over your head? Well, that is the life that Kristina Georgia Snow has everyone follow in Glass. Glass is the continuing book of Crank. Crank is about a innocent,17 year old girl named Kristina, who is on her way to graduating early when she has to go spend one month in the summer with her estranged father. While at her fathers house, she tries crank for the first time and falls in love with the monster. The book follows her journey with the monster and the consequences that come with it like hurting her friends and loved ones. The book ends with the teen becoming pregnant due to a product of rape. Glass picks up shortly after Kristina Snow, also known by her "alter ego" Bree, has the baby. She names her baby Hunter Seth.
Introduction: A phase change is a result from the kinetic energy (heat) either decreasing or increasing to change the state of matter (i.e. water, liquid, or gas.) Thus saying, freezing is the phase change from a liquid to a solid which results from less kinetic energy/heat. Also, melting is the phase change from a solid to a liquid which results from adding kinetic energy/heat. So, the freezing and melting point of something is the temperature at which these phase changes occur. Therefore, a phase change will occur when a vial of 10 mL of water is placed into a cup of crushed ice mixed with four spoonfuls with 5 mL of sodium chloride for 30 minutes. If 10 mL of water is placed in an ice bath, it will then freeze at 5 degrees Celsius because the kinetic energy will leave quicker with the ice involved. The purpose of this lab is to observe what temperature the water must be to undergo a phase change.
In high school and college many people who have taken chemistry may have learned that there are only four states of matter:solid, liquid, gas, and plasma. Where would glass fall within these states? Most people you ask might say it’s a solid of course. You can touch it and hit it and it will not give way to your hand. It makes up our windows and protects us from weather, so why would it not be a solid? Well surprisingly the state of glass, or the transition of melted glass to a more solid glass, seems to be a very debated subject in the science world. In fact, in Science Magazine’s 125th Anniversary issue which contained the world’s top one hundred science questions yet to be answered, question 22 was, “What is the nature of the glassy state?” and question 21 goes hand in hand, “Is superfluidity possible in a solid?”(Science,2005). Its seems as though glass is a state of its own, between liquid and solid.
A very important compound is dialuminum oxide Al2O3. The structure of dialuminum oxide is sometimes hexagonal. The structure is .It is one of the hardest substances known. It is formed by natural occurrence. Dialuminum oxide is formed from the reaction of metallic aluminum with oxygen gas. It is a white crystalline solid. Aluminum chloride has a formula of ALCl3. The structure is . It is mainly produced in the production of aluminum metal. It is white, but samples are often contaminated with iron trichloride, giving it a yellow color. The compound formula for dialuminum sulphide is Al2S3.The structure is . It is a ...
The Whole Winglfiled family has a problem distinguishing the difference what is real and what is not. At the end of the play only one character is able to escape the fireplace Tom he was so tired of her mother nagging and having all responsibility and was what he and did
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.