Surface area of calcium carbonate Essay Example

Surface area of calcium carbonate Essay Example Surface area of calcium carbonate Paper Surface area of calcium carbonate Paper Introduction: The experiment taking place is between calcium carbonate [CaCO3] and hydrochloric acid [HCl]. Calcium carbonate, also known as marble, is a metamorphic rock. This is a rock that is formed over long periods of time under high temperature and pressure. It is also formed when carbon dioxide reacts with calcium hydroxide to produce calcium carbonate. Calcium hydroxide + carbon dioxide calcium carbonate + Water Ca(OH)2(aq) + CO2(g) CaCO3(s) H2O(l) When an acid reacts with a carbonate the products are salt, water and carbon dioxide gas. When hydrochloric acid reacts with calcium carbonate the products are calcium chloride, water, and carbon dioxide. The formula for this reaction is: Hydrochloric acid + Calcium carbonate Calcium chloride + Water + Carbon dioxide HCl(aq) + CaCO3(s) CaCl2(aq) + H2O(l) CO2 As you can see above, in the reaction, the reactants are hydrochloric acid and calcium carbonate, and the products are calcium chloride, a salt, water and carbon dioxide. The speed at which the reactants will create the products is called the rate of reaction. This follows a theory called the kinetic theory. This theory states that all states of matter contain particles, which are constantly moving/vibrating [kinetic energy]. In solids the particles are positioned close together which allows them to vibrate slightly. Between them are strong bonds that hold them together in a fixed place. The particles present in liquid have further distance between them; therefore the forces of attraction are less than in solids. The particles have weaker bonds that allow them to move. The particles in a gas are much further apart than in a solid or liquid, and have very weak bonds that allow them to move quite freely. There are virtually nil forces of attraction between the gas particles. This therefore means that solids would have the slowest rate of reactivity, liquids would me in the middle, and gasses would have the fastest rates of reaction. The factors that would affect the rate of reaction would be: Concentration of hydrochloric acid. The higher the concentration of the acid the faster the rate of reaction will be. This is because there would be more particles of hydrochloric acid present in the reaction; therefore there would be more collisions, which would therefore results in a faster rate of reaction. The following diagram can show this overleaf: As you can see, in the low concentration of hydrochloric acid, there are 5 particles present, compared to 8 particles of calcium carbonate. In the higher concentration however, there are 10 particles of hydrochloric acid present, and the same amount of calcium carbonate particles present. This should therefore double the rate at which carbon dioxide is produced as there is now double the amount of collisions occurring. Catalyst catalysts are useful in a reaction as it speeds up the rate of reaction without being used up. Most catalysts are there to speed up the rate of reaction, however some can slow them down. The ones that speed up the rate of reaction are called activators, and those that slow down the rate of reaction are called inhibitors. For example, in the reaction where the enzyme (biological catalyst) breaks down hydrogen peroxide (H2O2) into water (H2O2) and oxygen (O2), glycerine is sometimes added, this is in order to slow down the rate at which hydrogen peroxide is broken down during storage. Most of the catalysts that are used are transition metals and their compounds, such as the making of margarine, where a nickel catalyst is used. The nickel catalyses an addition reaction, between a double bonded hydrocarbon (alkenes), the oil, and hydrogen. The result is a solid fatty product, which is margarine. By controlling the rate of reaction (i. e. how much catalyst is used) you can also control the solidity of the margarine. A catalyst allows a substance to react more easily by reducing the activation energy. This is where the energy needed in order to break the bonds is reduced. Therefore the particles require less energy to react, and the reaction occurs faster. Catalysts can be compared to getting from a-b in a car. The normal way would be by going through small roads, however using the motorway is like using a catalyst. This is as it takes less energy (petrol) to get there as well as far less time than compared to taking the smaller roads. Temperature when particle collide with each other, they do not always react. This is, as they do not have the sufficient kinetic energy for them in order to stretch or beak the bonds in order to form the products. In some reactions, only the particles with high energy can react. This sort of situation can be compared to a car crash; if two cars hit each other at low speeds, then hardly any damage will be done, however, if the cars hit each other at a higher speed, then a lot more damage would be done to both cars. Mass of calcium carbonate chips when you increase the mass of the chips, it means that there are more particles present for the hydrochloric acid to collide with. This would cause more collisions, which means a faster rate of reaction. Surface area of calcium carbonate chips in a reaction; if one of the reactants is a solid then the surface area of the solid will affect the rate of reaction. This is because the only particles that can collide with each other are the ones at the solid-liquid interface. This is the area in which the surfaces of the marble chips come in contact with the hydrochloric acid. This would therefore mean that the larger the surface area of the marble chips, the more collisions there would be, which a higher rate of reaction is. Diagram A and B are marble chips with the same masses. Diagram be has a higher surface area, and as you can see, there are more marble particles exposed to the surrounding, which would mean that there would be a larger amount of collisions in a given amount of time.

IEP Fraction Goals for Emerging Mathematicians

IEP Fraction Goals for Emerging Mathematicians Rational Numbers Fractions are the first rational numbers to which students with disabilities are exposed. Its good to be sure that we have all of the prior foundational skills in place before we start with fractions. We need to be sure students know their whole numbers, one to one correspondence, and at least addition and subtraction as operations. Still, rational numbers will be essential to understanding data, statistics and the many ways in which decimals are used, from evaluation to prescribing medication. I recommend that fractions are introduced, at least as parts of a whole, before they appear in the Common Core State Standards, in third grade. Recognizing how fractional parts are depicted in models will begin to build understanding for higher level understanding, including using fractions in operations. Introducing IEP Goals for Fractions When your students reach fourth grade, you will be evaluating whether they have met third grade standards. If they are unable to identify fractions from models, to compare fractions with the same numerator but different denominators, or are unable to add fractions with like denominators, you need to address fractions in IEP goals. These are aligned to the Common Core State Standards: IEP Goals Aligned to the CCSS Understanding fractions: CCSS Math Content Standard 3.NF.A.1 Understand a fraction 1/b as the quantity formed by 1 part when a whole is partitioned into b equal parts; understand a fraction a/b as the quantity formed by a parts of size 1/b. When presented with models of one half, one fourth, one third, one sixth and one eighth in a classroom setting, JOHN STUDENT will correctly name the fractional parts in 8 out of 10 probes as observed by a teacher in three out of four trials.When presented with fractional models of halves, fourths, thirds, sixths and eighths in with mixed numerators, JOHN STUDENT will correctly name the fractional parts in 8 out of 10 probes as observed by a teacher in three out of four trials. Identifying Equivalent Fractions: CCCSS Math Content 3NF.A.3.b: Recognize and generate simple equivalent fractions, e.g., 1/2 2/4, 4/6 2/3. Explain why the fractions are equivalent, e.g., by using a visual fraction model. When given concrete models of fractional parts (halves, fourths, eighths, thirds, sixths) in a classroom setting, Joanie Student will match and name equivalent fractions in 4 out of 5 probes, as observed by the special education teacher in two of three consecutive trials.When presented in a classroom setting with visual models of equivalent fractions, the student will match and label those models, achieving 4 out of 5 matches, as observed by a special education teacher in two of three consecutive trials. Operations: Adding and subtractingCCSS.Math.Content.4.NF.B.3.c Add and subtract mixed numbers with like denominators, e.g., by replacing each mixed number with an equivalent fraction, and/or by using properties of operations and the relationship between addition and subtraction. When presented concete models of mixed numbers, Joe Pupil will create irregular fractions and add or subtract like denominator fractions, correctly adding and subtracting four of five probes as administered by a teacher in two of three consecutive probes.When presented with ten mixed problems (addition and subtraction) with mixed numbers, Joe Pupil will change the mixed numbers to an improper fractions, correctly adding or subtracting a fraction with the same denominator. Operations: Multiplying and DividingCCSS.Math.Content.4.NF.B.4.a Understand a fraction a/b as a multiple of 1/b. For example, use a visual fraction model to represent 5/4 as the product 5 Ãâ€" (1/4), recording the conclusion by the equation 5/4 5 Ãâ€" (1/4) When presented with ten problems multiplying a fraction with a whole number, Jane Pupil will correctly multiple 8 of ten fractions and express the product as an improper fraction and a mixed number, as administered by a teacher in three of four consecutive trials. Measuring Success The choices you make about appropriate goals will depend on how well your students understand the relationship between models and the numeric representation of fractions. Obviously, you need to be sure they can match the concrete models to numbers, and then visual models (drawings, charts) to the numeric representation of fractions before moving to completely numeric expressions of fractions and rational numbers.