Recent questions in Chemistry

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Can the unique photophysical properties of lanthanide complexes be harnessed for efficient light harvesting and photocatalysis? Explore the photochemical properties of selected lanthanide complexes to demonstrate their potential applications in these fields.

asked Feb 3 in PhotoChemistry by MadisonJ035 (430 points)

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1 answer 45 views

Can the mechanical properties of ceramics be improved for use in high-temperature applications by adjusting the manufacturing parameters, such as sintering temperature and time?

asked Feb 3 in Materials Chemistry by Michele43T64 (350 points)

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Can the chemical modification of a polymer affect its optical properties and if so, how can we design a polymer with unique optical properties for use in advanced optical materials?

asked Feb 3 in Polymer Chemistry by SteffenBlund (290 points)

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Can SERS be used as a reliable technique to detect trace amounts of pesticides on food products?

asked Feb 3 in Surface Chemistry by KimberPilkin (210 points)

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Calculation of standard enthalpy change for the combustion of propane.If 5 moles of propane react completely in a bomb calorimeter under standard conditions, calculate the standard enthalpy change for the combustion of propane. The balanced chemical equation for the combustion of propane is:C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(g) Given the standard enthalpy of formation at 25°C and 1 atm for C3H8(g), CO2(g), H2O(g) are -103.8 kJ/mol, -393.5 kJ/mol and -241.8 kJ/mol respectively.

asked Feb 3 in Chemical thermodynamics by MollieMaddox (430 points)

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Calculating the standard enthalpy change for the vaporization of water is a common example used in chemistry. Suppose that you have 50.0 g of liquid water at 25°C and 1 atm pressure. What is the standard enthalpy change for the vaporization of this amount of water at its boiling point, which is 100°C and 1 atm pressure?

asked Feb 3 in Chemical thermodynamics by MalcolmBonil (510 points)

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Calculate the ΔHrxn for the combustion of methane gas (CH4) if the enthalpies of formation for methane, carbon dioxide, and water are -74.8, -393.5, and -285.8 kJ/mol respectively, using Hess's Law.

asked Feb 3 in Chemical reactions by TanyaPridgen (350 points)

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Calculate the zeta potential of a colloidal particle, given that the particle has a charge of -3.2 × 10^-19 C, a diameter of 250 nm, and is suspended in a solution with a dielectric constant of 78.3.

asked Feb 3 in Surface Chemistry by HalinaPeters (890 points)

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Calculate the yield of ibuprofen obtained from the given starting materials (2-methylpropylbenzene and carbon dioxide) during the synthesis process.

asked Feb 3 in Chemical synthesis by MinnaLerner (750 points)

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1 answer 53 views

Calculate the weight-average molecular weight of a polymer sample with the following information:- The polydispersity index (PDI) of the sample is 1.5.- The number-average molecular weight (Mn) of the sample is 20,000 g/mol. - The weight fraction (w) of the polymer with a molecular weight of 30,000 g/mol is 0.2, and the weight fraction of the polymer with a molecular weight of 10,000 g/mol is 0.8.

asked Feb 3 in Physical Chemistry by AubreyCato6 (350 points)

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Calculate the wavelength of light that must be absorbed for an electron in a hydrogen atom to transition from the n=3 to n=2 energy level, using the equation for energy of a hydrogen atom: E = -13.6/n^2 eV and the Planck constant, h = 6.626 × 10^-34 J s.

asked Feb 3 in Quantum Chemistry by ShellyClimps (830 points)

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Calculate the volume of 0.2 M hydrochloric acid required to completely neutralize 25 mL of 0.1 M sodium hydroxide solution.

asked Feb 3 in Chemical reactions by JaunitaDegre (410 points)

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1 answer 43 views

Calculate the vibrational frequencies and predict the infrared spectrum of methane (CH4) using quantum chemical methods.

asked Feb 3 in Quantum Chemistry by CharlaMonds (250 points)

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Calculate the vibrational frequencies and infrared spectra for a molecule of carbon dioxide (CO2) using quantum chemistry methods.

asked Feb 3 in Quantum Chemistry by StormyMeride (410 points)

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Calculate the vibrational frequencies and corresponding infrared spectra of HF molecule using quantum mechanical methods.

asked Feb 3 in Quantum Chemistry by LenaGladys98 (290 points)

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Calculate the vibrational frequencies and corresponding infrared spectra of carbon dioxide gas (CO2) using quantum chemical methods.

asked Feb 3 in Quantum Chemistry by Roy31W974524 (290 points)

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Calculate the value of standard enthalpy change for the sublimation of solid iodine at 25°C. The molar heat capacity of iodine (s) is 54.44 J/mol·K and its molar entropy of sublimation is 62.43 J/mol·K. The standard entropy of formation of iodine (s) is 62.80 J/mol·K.

asked Feb 3 in Chemical thermodynamics by RussellOdoms (190 points)

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1 answer 49 views

Calculate the total resistance of an electrochemical cell consisting of two half-cells where one half-cell has a copper electrode submerged in a 0.5 M CuSO4 solution, and the other half-cell has a zinc electrode submerged in a 1.0 M ZnSO4 solution. The copper electrode is connected to the zinc electrode through a salt bridge. The resistance of the salt bridge is 22 ohms, and the resistance of the copper and zinc electrodes are negligible.

asked Feb 3 in ElectroChemistry by Junko57E850 (270 points)

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1 answer 58 views

Calculate the total heat change when 100 ml of 0.5 M HCl is mixed with 100 ml of 0.5 M NaOH at 25°C. Assume the heat capacity of the solution is 4.18 J/(g°C) and the density of the solution is 1 g/mL. The enthalpy of neutralization of HCl and NaOH is -57.3 kJ/mol.

asked Feb 3 in ThermoChemistry by TwilaColby85 (330 points)

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1 answer 53 views

Calculate the theoretical yield of benzocaine that can be produced from 1.5 moles of p-aminobenzoic acid and excess ethanol, assuming complete conversion and a 95% yield.

asked Feb 3 in Chemical synthesis by DannySantora (390 points)

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