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How can we design a system using chemical principles to efficiently recover valuable metals such as gold, silver, and platinum from electronic waste without causing harm to the environment?

asked Mar 1 in Chemical engineering by TheScientist (138k points)

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What is the standard enthalpy change for the transition of ice to water if 50 grams of ice is heated from -10 °C to 50 °C? The molar mass of water is 18 g/mol and the specific heat capacity of ice and water are 2.09 J/g°C and 4.18 J/g°C, respectively.

asked Mar 1 in Chemical thermodynamics by TheScientist (138k points)

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How can we design a system for the production of hydrogen fuel that minimizes the use of non-renewable resources and reduces environmental impact?

asked Mar 1 in Chemical engineering by TheScientist (138k points)

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What is the standard enthalpy change for the reaction where 2 moles of hydrochloric acid react with 1 mole of magnesium hydroxide in aqueous solutions to produce 1 mole of magnesium chloride and 2 moles of water at 298 K and 1 atm pressure?

asked Mar 1 in Chemical thermodynamics by TheScientist (138k points)

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How can we design a system for the production of hydrogen fuel that maximizes efficiency and minimizes cost using chemical engineering principles?

asked Mar 1 in Chemical engineering by TheScientist (138k points)

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How can we control the lifetime of the excited state in a phosphorescent material to increase its efficiency as a light-emitting material, and what factors affect the lifetime of the excited state?

asked Mar 1 in PhotoChemistry by TheScientist (138k points)

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What is the expected pH of a 0.1 M solution of acetic acid (CH3COOH) with a pKa value of 4.76? Provide a detailed explanation of your answer, including any necessary calculations or formulas.

asked Mar 1 in Chemical bonding by TheScientist (138k points)

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In an electrochemical experiment, the anodic and cathodic Tafel slopes were found to be 100 mV/decade and 120 mV/decade, respectively. Calculate the value of exchange current density for the reaction.

asked Mar 1 in ElectroChemistry by TheScientist (138k points)

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In the production process of lubricants, how can the chemical engineer choose the most appropriate base oil and additives to achieve the desired viscosity and performance requirements while maintaining cost-effectiveness?

asked Mar 1 in Chemical engineering by TheScientist (138k points)

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What is the yield of acetylsalicylic acid obtained if 5 grams of salicylic acid and 10 grams of acetic anhydride are used in the preparation of acetylsalicylic acid through the reaction of esterification, assuming complete conversion?

asked Mar 1 in Chemical synthesis by TheScientist (138k points)

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What is the pH of a solution with a hydrogen ion concentration of 4.2 x 10^-5 M? Use a pH meter to determine the pH of the solution and compare it to the theoretical value calculated using the Henderson-Hasselbalch equation.

asked Mar 1 in Analytical Chemistry by TheScientist (138k points)

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What is the pH of a solution that has a hydrogen ion concentration of 2.5 x 10^-7 M? Determine the pH using a pH meter and state whether the solution is acidic, neutral, or basic based on the calculated pH value.

asked Mar 1 in Analytical Chemistry by TheScientist (138k points)

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What is the Gibbs free energy change (ΔG) for the reaction NH3(g) + HCl(g) → NH4Cl(s) at standard conditions (298 K and 1 atm)? Show the steps taken to calculate ΔG using quantum chemistry calculations.

asked Mar 1 in Quantum Chemistry by TheScientist (138k points)

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What is the yield of 2,4-dichloronitrobenzene produced from the reaction of 10 grams of nitrobenzene and excess chlorine gas, given that the reaction conditions were optimal and the purity of the final product was determined to be 95%?

asked Mar 1 in Chemical synthesis by TheScientist (138k points)

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What is the surface area of a solid material (in m²/g) if it has a nitrogen gas adsorption of 0.52 cm³/g at a relative pressure of 0.1 and assuming a monolayer coverage?

asked Mar 1 in Surface Chemistry by TheScientist (138k points)

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What is the standard enthalpy change for the fusion of 100 grams of ice at 0°C to liquid water at 0°C? Assume that the specific heat capacity of ice and water are 2.09 and 4.18 J/g·°C, respectively, and the enthalpy of fusion of ice is 6.01 kJ/mol.

asked Mar 1 in Chemical thermodynamics by TheScientist (138k points)

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What is the enthalpy change for dissolving 10 grams of sodium chloride (NaCl) in 100 mL of water at 25°C? The heat capacity of water is 4.18 J/(g·°C) and the enthalpy of formation of NaCl is -411.1 kJ/mol.

asked Mar 1 in ThermoChemistry by TheScientist (138k points)

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What is the purity of a sample of aspirin if its melting point is 134.5°C, compared to the literature value of 136°C? Calculate the percentage purity of the sample using the melting point range and known literature values.

asked Mar 1 in Analytical Chemistry by TheScientist (138k points)

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What is the standard enthalpy change for the reaction of methane gas and oxygen gas to form carbon dioxide gas and water vapor, given that all gases are at standard temperature and pressure conditions?

asked Mar 1 in Chemical thermodynamics by TheScientist (138k points)

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1 answer 80 views

What is the standard electrode potential for the reduction of Cu2+ to Cu at a temperature of 25°C? Use the half-reaction equation and the Nernst equation to calculate the potential.

asked Mar 1 in Physical Chemistry by TheScientist (138k points)

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