Calcium Iodide Molar Mass
Formula and structure: The chemical formula of sodium chloride is NaCl and its molar mass is 58. Percentage by mass = (mass of 5 moles SO3/molar mass of 3H2SO4. Notes: 1% iodine, 2% potassium iodide; use to differentiate bacteria based on their ability to hydrolyze starch Storage Code: Green—general chemical storage Sort by We Recommend New Arrivals Best Sellers Price, Low to High Price, High to Low Name - A-Z Name - Z-A.  In some embodiments, the method of making a scintillation Tl, Ln, A, and/or X- doped Lithium, Sodium or Cesium Iodide crystal having an energy resolution for a full energy peak in the range from 2. N 2 O 2) Benzene contains only carbon and hydrogen and has a molar mass of 78. 0% calcium, 12. 7 g of calcium iodide, CaI2? what mass of silver iodide (in grams) will. We will make the assumption that since x is going to be very small (the solubility is reduced in the presence of a common ion), the term "0. The major uses of potassium iodide include nutritional supplement in animal feeds. Do not exceed 0. View Homework Help - Mole Math Calculation Practice. 89 g, Part Two: Then you convert moles of calcium iodide to moles of silver iodide using the coefficients in the equation. formula NH2Cl, mass 51. The molar mass is a physical property, which is defined as the mass of a substance divided by its amount of substance in moles. Examiner Tip Calcium iodide would be acceptable but this is not the correct formula. –A dilute solution is one that contains a small. 61 g CO 2 and 9. 67 g sample of a hydrate of magnesium carbonate was carefully heated, without decomposing the carbonate, to drive off the water. Molar mass of CaI2 = 293. Check Your Learning What is the molar mass of a protein if a solution of 0. 0% carbon, 6. Experimental lattice energy /kJ mol–1 Theoretical lattice energy /kJ mol–1 Potassium iodide, KI(s) – 651 – 636 . (A) Write a balanced chemical equation for this reaction. *solid*silver*hydroxide*and*hydrobromicacid* * _____* * e. What is the name given to the electrons in the highest occupied energy level of an atom? a. 433 mol of calcium nitrate. Use the following data to calculate the enthalpy of hydration for calcium chloride and calcium iodide. We are proffering international marketplace with cheap rates for magnesium chloride and chemicals, dyes & solvents products created in china. 2% O, and 7. ! 151! Chapter9:!SolutionsandSolutionReactions. 89 g, Part Two: Then you convert moles of calcium iodide to moles of silver iodide using the coefficients in the equation. A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and plus (+) and minus (−) signs. Titration of Ca(OH) 2 with 0. *Attached* 2. Barium Iodide is a toxic inorganic compound existing both in its anhydrous and hydrated forms. Below are the values of the Ksp product constant for the most common salts. Conformer generation is disallowed since MMFF94s unsupported element, MMFF94s unsupported atom valence, mixture or salt. AP Chemistry Summer Assignment. Instructions. All sulfates are soluble except calcium sulfate and barium sulfate. 0259 g · mol–1. 738088, Heavy Atom Count of 3, Complexity of 2. Experimental lattice energy /kJ mol–1 Theoretical lattice energy /kJ mol–1 Potassium iodide, KI(s) – 651 – 636 . asked by Faith 1 on October 11, 2016; chemistry. This colourless deliquescent solid is highly soluble in water. 12 g/mol, what is the molecular formula of the compound? 15. A mole is an amount, refers to Avogadros number which is 6. Copper(I) Iodide offered by Alpha Chemika - an ISO 9001:2000 standard certified organization and renowned as a leading manufacturer, supplier & exporter of all laboratory chemicals including Copper(I) Iodide & based in Mumbai, India. Solubility of NaNO 3 =21. Atomic Mass of Iodine. Calculate the molar mass of calcium iodide. A sample contains an unknown amount of the mineral calcite, CaCO3. Sodium hydroxide (NaOH): 2 g/mol Water (H2O): 4 g/mol Glucose (C6H12O6): 2 g/mol Calcium sulfate (CaSO4): 1 g/mol Magnesium phosphate (Mg3(PO4)2): 1 g/mol. Formulas of binary ionic compounds & molecular compounds. When solutions of potassium iodide and lead (II) nitrate are combined, the products are potassium nitrate and lead (II) iodide. In the following reaction, how many grams of silver iodide, AgI, will be produced from 84. Its properties are similar to those for related salts, such as calcium chloride. Home; About Us; Make Your Order; Contact Us; Login; Arabic. - [Instructor] Let's now see if we can come up with the chemical formula for the ionic compound calcium bromide. 90447*2 ›› Percent composition by element. The molar mass for potassium iodide is 166,0028. therefore the molar mass of potassium. 32x1025 atoms of cobalt? Find the molar mass of Mg3(PO3)2. Atomic Mass of Iodine. High purity, submicron and nanopowder forms may be considered. 904 grams per mole. 0% oxygen by mass. There is no warranty of accuracy or completeness of any information contained herein. 5×10–14 Cadmium oxalate CdC2O4 1. We are considered as one of the leading manufacturers and suppliers of an excellent stock of Calcium Iodide (CaI 2). -A dilute solution is one that contains a small. 98 g/mole and the molar mass of iodine is 126. 80 % H , and 15. Magnesium iodide is the name for the chemical compounds with the formulas MgI 2 and its various hydrates MgI 2 (H 2 O) x. 2) Benzene contains only carbon and hydrogen and has a molar mass of 78. 10 x 10^2 g/mol) is prepared by mixing equal masses of the two. Ca3(PO4)2 is a white powder at room temperature. 5% O by mass and has a molar mass of about 206 g/mol. It is in solid form and is highly soluble in water. It is a solid stuff of white color with a yellowish tint. We formulate Calcium Iodide in complete compliance with the industry standards. 0% carbon, 6. 9g or NaNO 3 x 100 g/ 25 g =87. Calculate the molar mass of the compound, MM. Calcium iodide ( chemical formula CaI2) is the ionic compound of calcium and iodine. 5 mole sample? c) How many oxygen atoms are present in the 1. solid copper reacts with lead(ll) nitrate(aq) to produce solid lead and copper(ll) nitrate(aq) doc d. Once you have the molar mass, multiply the number of grams of solute by 1 over the molar mass to convert the grams into moles. formula CHI , molar mass —84g/mOl. The IO 3-ion is an oxidizing agent. Determine the empirical and molecular formula of each of the following substances: a. 46 g/mol (Octahydrate) Is Barium Hydroxide Soluble In Water? The solubility of Barium Hydroxide is moderate in water. What fraction of atoms in morphine is accounted for by carbon? c. Calculations are based on hydrochemistry program PhreeqC. Find the formula mass: KCl_ Calcium iodide_ CuO_ 2. Solution: Moles of carbon = 10 g 1 mol C3 315 mg C 1 mg 12. 8×10 -5 Aluminum phosphate AlPO 4 6. 90447*2 ›› Percent composition by element. Strontium iodide (SrI 2) is a salt of strontium and iodine. The outstanding class of magnesium chloride is In-stock for purchase. Ca(NH 3) + 2NH 4 I → CaI 2 + 2NH 3 + H 2 (g). Treating an iodide with manganese dioxide and sulfuric acid sublimes the iodine. Solubility Constant Determining the solubility The solubility of Ca(IO 3) 2 will be determined using an indirect redox titration. 459174: Magnesium: 24. orbital electrons c. It is used in photography. Underline acids. Determine the empirical formula. Round your answer to the hundredths place. Because there are two NO 3 - ions for each Ca 2+ ion in the compound, each mole of Ca(NO 3 ) 2 that dissolves dissociates into 1 mol of Ca 2+ and 2 mol of NO 3 -. 10 x 10^2 g/mol) is prepared by mixing equal masses of the two. 2) Benzene contains only carbon and hydrogen and has a molar mass of 78. A method for producing a calcium silicate hydrate-comprising hardening accelerator in powder form, which comprises the steps of (a) providing an aqueous suspension comprising calcium silicate hydrate; (b) mixing at least one calcium compound, selected from calcium acetate, calcium formate, calcium hydroxide, calcium oxide, and mixtures of two. 3×10–9 Calcium hydrogen phosphate CaHPO4 1×10–7 Calcium hydroxide Ca(OH)2 5. 0 moles per liter of solution in some cases. In related terms, another unit of mass often used is Dalton (Da) or unified atomic mass unit (u) when describing atomic masses and molecular masses. Solubility Rules: Greater than 0. calcium iodide Physical appearance: Empirical formula (Hill's system): CaI 2 Structural formula: CaI2 Molar/atomic mass: 293. 7% N by mass; its molar mass is about 180 amu. Potassium iodide–polyethylene glycol catalyzed cycloaddition reaction of epoxidized soybean oil fatty acid methyl esters with CO 2 Article (PDF Available) in RSC Advances 8(54):30860-30867. When the formula contains no carbon, all the elements, including hydrogen, are listed alphabetically. Conductivity values displayed in yellow are questionable; please contact the SmartMeasurement factory for assistance. 38,522 results chemistry The molar mass of HCl is 36. The relative formula mass of a substance is the sum of the relative atomic masses of the elements present in a formula unit. Strategy Plan. Calcium Iodide is the inorganic compound with the formula CaI 2. What mass of rhodium contains as many atoms as there are in a) gallium atoms in 36. Epinephrine (adrenaline) a secreted into the bloodstream in. 1) Determine the moles of calcium iodide used to make the solution 2) Determine the mass of solvent used to make the solution. The molar mass is calculated by adding up the relative atomic weights of each element in a chemical species according to the chemical formula of that species. - [Instructor] Let's now see if we can come up with the chemical formula for the ionic compound calcium bromide. If a particular chemical is not listed, or if you would like application assistance with an electromagnetic flowmeter application, please feel free to contact SmartMeasurement TM 's U. Main page (Russian) Search in database (English) Sitemap (Russian) Properties of substance: cobalt(II) chloride Physical appearance: trigonal crystals Empirical formula (Hill's system):. What is the sum of the coefficients when the molecular equation is balanced in standard form?. 40,078+126,90447·2. atomic mass. In addition, Calcium chloride is widely used as a De-icer since it is effective in lowering the melting point when applied to ice. Stable, but may be light, air or moisture sensitive. Calculate the molarity. This online resource is an inquiry-based learning sequence that includes hands-on activities, digital interactives, animations and videos on earth and space science. 5 mole sample? c) How many oxygen atoms are present in the 1. 5 mol sample 2. It will calculate the total mass along with the elemental composition and mass of each element in the compound. 4 A mass of 10. 3 X 10 22 formula units of calcium iodide? Episode 701 Problems: Fill in masses from lab data and solve. Write and balance the equation for this reaction to answer the following question. 5 % O by mass and has a molar mass about 206 g/mol. asked by jennifer on January 31, 2014 Chemistry …. Find the mass of 5 moles SO3. 7% hydrogen, and 53. View Homework Help - Mole Math Calculation Practice. Strontium Chromate c. Calculate the mass of precipitate produced when 50. For example, aluminum nitrate has molar mass which is equal to 212. The molar volume can be calculated from the density of the gas using the formula: density = For example: What is the molar volume of ammonia [density = 0. Molar Mass?g CaI. How many moles are 1. ? CaCl2 lattice energy is -2247 kj/mol delta H of solution is -46 kj/mol CaI2 lattice energy is -2059 kj/mol delta H of solution is -104 kj/mol The enthalpy of energy should just be in kJ. Its properties are similar to those for related salts, such as calcium chloride. Expert Answer A)CaSO4 + 2NaI --> CaI2 + Na2SO4 B) Number of moles of CaSO4,n = m/M = 34. KHP is an acid with one acidic hydrogen and a molar mass of 204. A 10 mL sample of 1. The peaks in the mass spectrum A41 Answers to Selected Exercises. Ca3(PO4)2 is a white powder at room temperature. Calcium iodide slowly reacts with oxygen and carbon dioxide in the air, which releases the iodine ions and forms calcium carbonate. Find the mass of 5 moles SO3. How many moles are 1. Precipitation Titration: Determination of Chloride by the Mohr Method by Dr. When the formula contains no carbon, all the elements, including hydrogen, are listed alphabetically. Calcium Iodide CaI2 Molar Mass, Molecular Weight. ow many grams of CuC12 are needed to make a 1. Hydrate or anhydrous forms may be purchased. 1%), and by the addition of stabilizers such as sodium thiosulfate and calcium hydroxide, and/or drying agents such as magnesium carbonate or calcium carbonate. This colourless deliquescent solid is a salt that is highly soluble in water. Calcium iodide ( chemical formula CaI 2 ) is the ionic compound of calcium and iodine. The IO 3-ion is an oxidizing agent. The molar mass of fructose is 180. Its properties are similar to those for related salts, such as calcium chloride. The hydration enthalpies for calcium and chloride ions are given by the equations: The following cycle is for calcium chloride, and includes a lattice dissociation enthalpy of +2258 kJ mol-1. a) Calculate the mass in grams, of 0. Examples of molar mass computations: NaCl, Ca (OH)2, K4 [Fe (CN)6] , CuSO4*5H2O , water , nitric acid , potassium permanganate , ethanol , fructose. Insoluble in ether Alfa Aesar 22395. 0, so its molar mass is 44. molar mass of the element. For every one. It can be created by neutralising hydrochloric acid with calcium hydroxide. Recall that the conversion factor relating grams to moles is molar mass. It is a white coloured crystalline solid at room temperature, highly soluble in water. 5 g/ 51 the empirical and formula Of each Of the following a-ibuprofen, a headache Contains 75. Purpose To determine the molar volume of H 2 gas at STP. Well, you got us here mate. Mass of crucible, cover, and contents before heating = 23. Ca(NH 3) + 2NH 4 I → CaI 2 + 2NH 3 + H 2 (g). Stable, but may be light, air or moisture sensitive. 4 g/mol BaSO4) = 0. The molar mass of an element or compound has a unit of grams per mole, i. Solubility Products of Selected Compounds. Aqueous ions tend to react faster than species in other states of matter: Solid lead(II) nitrate will react with solid potassium iodide, but the reaction is really, really slow. Formula: Ca3(PO4)2. Theories explored for the experiment included heterogeneous mixture, molar volume, standard temperature and pressure, Dalton's law of partial. STP is standard temperature and pressure, which is, 0 o C and 101 Kpa. Molar mass (molar weight) is the mass of one mole of a substance and is expressed in g/mol. Senior labs have access to a safety shower and eyewash station. 5 Use dimensional analysis to convert between the mass, number of moles and number of particles of a substance. Catalyzes exothermic polymerization of. the molecular mass of this unknown compound is 180 amu. Unit 10A Stoichiometry Notes Stoichiometry is a big word for a process that chemist's use to calculate amounts in reactions. How many atoms are in 10. Determine the empirical and molecular formula of each of the following substances: a. mass of CaI2 taken = 12. The preservation of medical laboratory blood samples, mining of sea water for magnesium, formulation of over-the-counter medicines such as Milk of Magnesia and antacids, and treating the presence of hard water in your home's water supply are just a few of the many tasks that involve controlling the equilibrium between a slightly soluble ionic solid and an aqueous solution of its ions. Individual compounds include the anhydrous material (x = 0), the hexahydrate (x = 6), and the rare dihydrate (x = 2). KHP is an acid with one acidic hydrogen and a molar mass of 204. 8 g of KCl is dissolved in 225 mL of water.  Calcium iodate is used in the manufacture of disinfectants, antiseptics, and deodorants. That is, the mass of the products must be the same as that of the reactants. 4 L of a gas at STP ( You do not need to worry about this yet ) Each definition can be written as a set of two conversion factors. Results revealed a 990 Da shift between the experimental mass (13,034 Da) and the theoretical mass (12,044 Da) of the recombinant protein, which is compatible with the addition of ten phosphoryl groups (80 Da) and a single N-linked glycan (161 Da) as previously hypothesized via NetNGlyc 1. The structure of anhydrous Barium Iodide bears similarity to that of lead (II) chloride. !! When!the!exact!composition!of!a!mixture!is!known,!it!is!called!a!solution. Chapter 4 Homework Questions TEXTBOOK HOMEWORK Chapter 3 3. MAGNETIC SUSCEPTIBILITY OF THE ELEMENTS AND INORGANIC COMPOUNDS When a material is placed in a magnetic field H, a magnetization (magnetic moment per unit volume) M is induced in the material which is related to H by M = κH, where κ is called the volume susceptibility. Yes because when you calculate the molar mass of the compounds in the equation, the total molar masses on both sides of the equation will equal. KHP is an acid with one acidic hydrogen and a molar mass of 204. 7% N by mass; its molar mass is about 180 amu. We formulate Calcium Iodide in complete compliance with the industry standards. Stoichiometry. Second, you must calculate the number of mols of Calcium present in the compound. 56 torr at 25 °C?. The units for molar mass are g mol -1 or grams per mole. 88694 g/mol. 433 mol of calcium nitrate. How many grams of calcium carbonate are required for complete reaction with 35. Solution: We can use the data provided to determine the concentration of Ag + ions in the waste, from which the number of moles of Ag + in the entire waste solution can be calculated. Chemical use in junior laboratories: Our science faculty is moving to a new, purpose-built facility next year. 2 L Ca (OH) b. Molar Mass. Solubility in water, acetone, ammonia liquid, methanol, ethanol,. All sodium, potassium, and ammonium salts are soluble. It is soluble in water and explodes when exposed to prolonged fire or heat. It will calculate the total mass along with the elemental composition and mass of each element in the compound. In other words, if the calcium ion concentration in today's experiment was found to be 0. 74% H by mass. All carbonates, sulfides, oxides and hydroxides are insoluble. You need to understand electrode equations, interconvert mass and moles and use the molar volume where gases are formed at the electrodes in electrolytic processes. What is the sum of the coefficients when the molecular equation is balanced in standard form?. 3) Calcium carbonate decomposes upon heating, producing calcium oxide and carbon dioxide gas. The second isotope is 81Br with mass equal to 161. If the substance is made of simple molecules, this mass may also be called the relative molecular mass. Calcium iodide. It will calculate the total mass along with the elemental composition and mass of each element in the compound. Computing the molar mass? Using this equation for all questions: 3 CaI2 (aq) + 2 (NH4)3PO4 (aq) --> Ca3(PO4)2 (s) + 6 NH4I (aq) 1. Calculate the molar mass of calcium iodide. Use uppercase for the first character in the element and lowercase for the second character. Solubility in water, acetone, hydrazine, pyridine, aniline, sulfur dioxide, formic acid, ethanol,. The mass of the Earth atmosphere is 5. Include phase notation in the equations. Step 4 - Set up the problem so that units cancel and you are left with only the units you need. 54 mol/L calcium nitrate solution is added to 47. 3×10 -19 Barium carbonate BaCO 3 5. Assume that. 5 % O by mass and has a molar mass about 206 g/mol. Round your answer to the thousands place. molar mass of compound = 0. Molar mass of the compound is 189. Iodine has seven electrons in valence shell and requires one electron to complete outer most shell. Iodide compounds are water soluble; however, iodide-rich solutions act as better dissolution agents for creating iodide solutions. 74% H by mass. 40,078+126,90447·2. 3×10 -19 Barium carbonate BaCO 3 5. 4 L of a gas at STP ( You do not need to worry about this yet ) Each definition can be written as a set of two conversion factors. Solubility in water, acetone, ammonia liquid, methanol, ethanol,. Examples: Fe, Au, Co, Br, C, O, N, F. Molar mass of an element (g/mol)equals the _____ _____ of the element in grams What would be the mass of 5. Convert grams Calcium Iodate to moles or moles Calcium Iodate to grams. From the molarity formula, you can calculate volume, grams or the moles of solute. Calcium chloride. The mass of gas occupying 22. In the 1990's nutritionists warn that eating too much phosphorous can fluster the body's ability to absorb calcium and raise the danger of osteoporosis. Experimental lattice energy /kJ mol–1 Theoretical lattice energy /kJ mol–1 Potassium iodide, KI(s) – 651 – 636 . 5 by mass and has a molar mass about 206 g/mol. Concentration of Solutions and Molarity The concentration of a solution is a measure of the amount of solute that is dissolved in a given quantity of solvent. The maximum yield of iodine. 1 g) + (2 × 126. No ads = no money for us = no free stuff for you! Weight/Volume Percentage Concentration Calculations. It is defined to be 1/12 of the mass of one atom of carbon-12 and in older works is also abbreviated as "amu". 00 g/mol because of the added mass of one mole of water per mole of sodium carbonate. 40,078+126,90447·2. Of the various methods of expressing solution concentration the most convenient for general laboratory use is molarity, which is defined: Moles of solute n solute. Calcium iodide solution Sodium chloride solution Potassium carbonate solution Aluminum hydroxide solution Glucose solution Sulfuric acid Formula CaI 2 NaCl K 2 CO 3 Al(OH) 3 C 6 H 12 O 6 H 2 SO 4 Electrolyte or non-electrolyte Electrolyte Electrolyte Electrolyte Electrolyte Non-electrolyte Electrolyte Ions in solution Ca2+, 2 I-Na+, Cl 2 K+, CO. The molar ratios of Ca, P and I were taken as 10, 6 and 2, respectively. The concentration of solid AgCl can be calculated from its density and the molar mass of AgCl. Give your answer to the correct number of significant figures. It is also used in cat food as a source of iodine. Aluminum Carbonate. Calcium Iodide CaI2 Molar Mass, Molecular Weight. When solutions of potassium iodide and lead (II) nitrate are combined, the products are potassium nitrate and lead (II) iodide. The formation of a precipitate when aqueous calcium iodide and aqueous potassium sulfate are mixed. It is used in photography. Glucose contains 40. Calculate the molar mass of the compound, MM. Calculations are based on hydrochemistry program PhreeqC. Find the empirical and molecular formulas of benzene. And like always, if you are inspired, pause the video and see if you can come up with it on your own. Magnesium iodide is the name for the chemical compounds with the formulas MgI 2 and its various hydrates MgI 2 (H 2 O) x. Round your answer to the thousands place. Abstract The United States Department of Energy is building the Hanford Waste Treatment and Immobilization Plant (WTP) in south-central Washington State to immobilize a portion of the stored high-level radioactive wastes generated by decades of producing nuclear. Molar mass of CaI2 = 293. Potassium iodide, also called KI is a salt of stable (not radioactive) iodine. If larger masses of calcium. E) Now that you know which reactant get used up, go back to part B or C and convert moles of calcium iodide to grams using the molar mass of calcium iodide. There is no warranty of accuracy or completeness of any information contained herein. A chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and plus (+) and minus (−) signs. Molecular Formula. To find more Calcium iodide information like chemical properties, structure, melting point, boiling point, density, molecular formula, molecular weight, physical properties and toxicity information. Repeat the experiment six more times, increasing the mass of calcium carbonate by about 0. 0% carbon, 6. Calcium bromide is the name for compounds with the chemical formula Ca Br 2 (H 2 O) x. shouguang dinghao trading co. A 10 mL sample of 1. Reduction of purple permanganate ion to the colorless Mn+2 ion, the solution will turn from. Options for hiding the symbol or name of the elements provide a handy learning aid for memorizing the periodic table. Aluminum hydroxide Al(OH) 3 1. Chromium(II) Iodide is generally immediately available in most volumes. He analyzes some of the solution from the final volumetric flask and finds that the iodide ion concentration is 0. ow many grams of CuC12 are needed to make a 1. Small pure smaples of calcum iodide may be made through the reaction of calcium metal in liquid ammonia with ammonium iodide. In this case, the smallest quantity is for calcium at 0. Thus, molar mass allows us to quickly convert a mass into a. It is used in photography. Magnesium iodide is the name for the chemical compounds with the formulas MgI 2 and its various hydrates MgI 2 (H 2 O) x. The molar ratios of Ca, P and I were taken as 10, 6 and 2, respectively. 738088, Monoisotopic Mass of 317. Molarity Calculations. Solubility Constant Determining the solubility The solubility of Ca(IO 3) 2 will be determined using an indirect redox titration. A 10 mL sample of 1. In related terms, another unit of mass often used is Dalton (Da) or unified atomic mass unit (u) when describing atomic masses and molecular masses. 5 % O by mass and has a molar mass about 206 g/mol. All carbonates, sulfides, oxides and hydroxides are insoluble. Molar Mass: 310. The mass of gas occupying 22. 88694 g/mol. How many formula units are in 12. Round your answer to the hundredths place. Convert grams Calcium Iodide to moles or moles Calcium Iodide to grams. Calculate the mass of precipitate produced when 50. AP Chemistry, Fall 2016 Roswell High School 20.