Chemistry

4. (20 pts.) Below is a liquid-solid phase diagram for a mixture of two components, A and B. 700 T(K) 800 750 p liquid 650 600 550 500 450 400 40 350 300 0 01 02 03 04 05 06 07 08 09 1 24 (a) For the points labeled 1 through 4 along the vertical line at 20.2, provide the number of phases pret a description of each phase, and the mole fraction of B in each phase. (To receive full credit, descriptions must be clear and unambiguous.) I (b) What is the melting temperature of pure A? © What is the melting temperature of pure B? (d) What is the eutectic temperature? (e) What is the eutectic composition? ( What is the freezing point of a liquid with 2-0.27 (C) For the two-component system described by the phase diagram in problem #4, sketch cooling curves for solutions with Zp = 0,25 = 0.2, and zp = 0.4. The cooling curves should start at 800 K. What quantity does the horizontal axis correspond to?

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The Environmental Protection Agency (EPA) wants to restrict the amount of pollutants added by a company to the river water. The concentrations of phenol and nitrogen in the water are to be restricted to, respectively, P and N lbs. MG (million gallons) on a daily basis. The river has a flow of M MG/day. The company diverts a portion of the river water, adds the pollutants, namely, phenol and nitrogen, to it, and sends the water back to the river. The company has four possible ways to treat the water it uses before returning it to the river. The characteristics of each treatment are given in the following table:

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The Environmental Protection Agency (EPA) wants to restrict the amount of pollutants added by a company to the river water. The concentrations of phenol and nitrogen in the water are to be restricted to, respectively, P and N lbs. MG (million gallons) on a daily basis. The river has a flow of M MG/day. The …

The Environmental Protection Agency (EPA) wants to restrict the amount of pollutants added by a company to the river water. The concentrations of phenol and nitrogen in the water are to be restricted to, respectively, P and N lbs. MG (million gallons) on a daily basis. The river has a flow of M MG/day. The company diverts a portion of the river water, adds the pollutants, namely, phenol and nitrogen, to it, and sends the water back to the river. The company has four possible ways to treat the water it uses before returning it to the river. The characteristics of each treatment are given in the following table: Read More »

Five grams of an organic solid is dissolved in 100 ml of H20 (solvent 1). Which of the following extraction methods will remove the largest amount of the organic solid from the aqueous solution? Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer. a Three 50 ml portion extractions with ether (solvent 2) b Two 50 ml portion extractions with ether (solvent 2) с One 150 ml portion extractions with ether (solvent 2) d One 50 ml portion extractions with ether (solvent 2) o Q.7.2-Post-Lab Caffeine Extraction Homework. Unanswered The pka of 2,5-dinitrophenol is 5.15. Will it dissolve in sodium carbonate solution? Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer. a No, typically organic phenols do not dissolve i aqueous solution b No, because the 2,5-dinitrophenolis basic с Yes, the 2,5-dinitrophenol will react with sodium carbonate, and the resulting salt will dissolve in aqueous solution d Yes, any phenol is soluble in sodium carbonatelution

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EXPERT ANSWER Organic extraction Ans: a) Three 50mL extraction with ether (solvent 2). The multiple extraction is effective than the bulk single extraction. Hence Three 50mL would be best. 2,5-Dinitro phenol: Ans: C The 2,5-Dinitrophenol pKa = 5.5, Hence it will react with Sodium bicarbonate (pKa of HCOO– = 6.4, higher than pKa of 2,5-Dinitro phenol) …

Five grams of an organic solid is dissolved in 100 ml of H20 (solvent 1). Which of the following extraction methods will remove the largest amount of the organic solid from the aqueous solution? Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer. a Three 50 ml portion extractions with ether (solvent 2) b Two 50 ml portion extractions with ether (solvent 2) с One 150 ml portion extractions with ether (solvent 2) d One 50 ml portion extractions with ether (solvent 2) o Q.7.2-Post-Lab Caffeine Extraction Homework. Unanswered The pka of 2,5-dinitrophenol is 5.15. Will it dissolve in sodium carbonate solution? Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer. a No, typically organic phenols do not dissolve i aqueous solution b No, because the 2,5-dinitrophenolis basic с Yes, the 2,5-dinitrophenol will react with sodium carbonate, and the resulting salt will dissolve in aqueous solution d Yes, any phenol is soluble in sodium carbonatelution Read More »

1. Convert each of the following Lewis structures to condensed structures and Line structures. Please keep your answers within the boxes below the Lewis structures. a) b) Line structure: 2. Determine the molecular formulas and then write condensed structures for the following Line structures in the boxes provided. \begin{tabular}{|l|l|} \hline Molecular formula: \\ \hline Molecular formula: \end{tabular} Do these structures represent the same molecule? Explain. 3. Determine the molecular formulas and then draw Line structures for the following condensed structures in the boxes provided. a. (CH 3 ​ ) 3 ​ CCH 2 ​ CH 2 ​ COCH 2 ​ CHBrCH(CH 3 ​ ) 2 ​ b. (CH 3 ​ ) 3 ​ CCHCHCHOHCHCH 2 ​ CHBCH(CH 3 ​ ) 2 ​ c. (CH 3 ​ ) 2 ​ CHCHBrCH 2 ​ CO(CH 2 ​ ) 2 ​ C(CH 3 ​ ) 3 ​ b) Molecular formula: Line structure: Line structure:

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2. Define USABILITY as the standard set by ISO (9241-11) and discuss the key properties or specifications contained in the definition with pragmatic scenarios 3. Identify any four (4) factors that can be used to quantify software userfriendliness for usability testing. 4. Evaluation is concerned with gathering data about the usability of a design or product by a specified group of users for a particular activity within a specified environment or work context. As an evaluation expert, discuss four evaluation approaches you will recommend for analysis throughout the design processes and under what favorable scenario can each approaches be executed. 5. In HCI, usability requires project management and careful attention to requirements analysis and testing for clearly defined objectives. Discuss four (4) major reasons why requirements analysis needs careful attention.

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EXPERT ANSWER 𝟏)𝐒𝐨𝐥𝐮𝐭𝐢𝐨𝐧:-𝐆𝐢𝐯𝐞𝐧 𝐝𝐚𝐭𝐚:-𝐃𝐢𝐟𝐟𝐞𝐫𝐞𝐧𝐭𝐢𝐚𝐭𝐞 𝐛𝐞𝐭𝐰𝐞𝐞𝐧 𝐟𝐨𝐫𝐦𝐚𝐥 𝐚𝐧𝐝 𝐢𝐧𝐟𝐨𝐫𝐦𝐚𝐥 𝐮𝐬𝐚𝐛𝐢𝐥𝐢𝐭𝐲 𝐭𝐞𝐬𝐭𝐢𝐧𝐠. 𝐅𝐨𝐫𝐦𝐚𝐥 𝐮𝐬𝐚𝐛𝐢𝐥𝐢𝐭𝐲 𝐭𝐞𝐬𝐭𝐢𝐧𝐠:-𝐅𝐨𝐫𝐦𝐚𝐥 𝐮𝐬𝐚𝐛𝐢𝐥𝐢𝐭𝐲 𝐭𝐞𝐬𝐭𝐢𝐧𝐠 𝐮𝐬𝐞𝐬 𝐚 𝐫𝐞𝐬𝐞𝐚𝐫𝐜𝐡 𝐟𝐚𝐜𝐢𝐥𝐢𝐭𝐲, 𝐜𝐨𝐦𝐩𝐥𝐞𝐭𝐞 𝐰𝐢𝐭𝐡 𝐨𝐧𝐞-𝐰𝐚𝐲 𝐦𝐢𝐫𝐫𝐨𝐫𝐬 𝐟𝐨𝐫 𝐨𝐛𝐬𝐞𝐫𝐯𝐚𝐭𝐢𝐨𝐧.• 𝐓𝐡𝐞 𝐭𝐞𝐬𝐭 𝐢𝐬 𝐮𝐬𝐮𝐚𝐥𝐥𝐲 𝐩𝐞𝐫𝐟𝐨𝐫𝐦𝐞𝐝 𝐨𝐧 𝐚 𝐥𝐢𝐯𝐞 𝐬𝐢𝐭𝐞 𝐨𝐫 𝐚 𝐡𝐢𝐠𝐡-𝐟𝐢𝐝𝐞𝐥𝐢𝐭𝐲 𝐞𝐥𝐞𝐜𝐭𝐫𝐨𝐧𝐢𝐜 𝐩𝐫𝐨𝐭𝐨𝐭𝐲𝐩𝐞 𝐚𝐧𝐝 𝐨𝐟𝐭𝐞𝐧 𝐫𝐞𝐬𝐮𝐥𝐭𝐬 𝐢𝐧 𝐚 𝐟𝐨𝐫𝐦𝐚𝐥 𝐮𝐬𝐚𝐛𝐢𝐥𝐢𝐭𝐲 𝐫𝐞𝐩𝐨𝐫𝐭.• 𝐅𝐨𝐫𝐦𝐚𝐥 𝐭𝐞𝐬𝐭𝐢𝐧𝐠 𝐢𝐬 𝐛𝐞𝐬𝐭 𝐮𝐬𝐞𝐝 𝐟𝐨𝐫 𝐥𝐚𝐫𝐠𝐞 𝐨𝐫𝐠𝐚𝐧𝐢𝐳𝐚𝐭𝐢𝐨𝐧𝐬 …

2. Define USABILITY as the standard set by ISO (9241-11) and discuss the key properties or specifications contained in the definition with pragmatic scenarios 3. Identify any four (4) factors that can be used to quantify software userfriendliness for usability testing. 4. Evaluation is concerned with gathering data about the usability of a design or product by a specified group of users for a particular activity within a specified environment or work context. As an evaluation expert, discuss four evaluation approaches you will recommend for analysis throughout the design processes and under what favorable scenario can each approaches be executed. 5. In HCI, usability requires project management and careful attention to requirements analysis and testing for clearly defined objectives. Discuss four (4) major reasons why requirements analysis needs careful attention. Read More »