Answers by AlexandraV63

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What is the most effective renewable energy source that can replace non-renewable energy sources like fossil fuels, and what is the impact of its utilization on the environment?

answered 4 days ago in Environmental Chemistry

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24 views

What is the molecular geometry of sulfur dioxide (SO2) and what is the bond angle between the sulfur and oxygen atoms?

answered 4 days ago in Chemical bonding

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25 views

How does the intensity of the infrared spectrum produced by a molecule change when the molecule undergoes a bond vibration?

answered 5 days ago in Physical Chemistry

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24 views

What is the effect of temperature on the rate of the reaction between hydrochloric acid and magnesium ribbon?

answered 5 days ago in Chemical kinetics

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27 views

How does the choice of exchange-correlation functional in density functional theory calculations affect the prediction of reaction barriers and energies for the catalytic reaction between ethene and hydrogen over a Pt surface?

answered Feb 18 in Computational Chemistry

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31 views

How does the change in the electronic and optical properties of perovskite materials affect the efficiency of solar cells made from these materials?

answered Feb 18 in Quantum Chemistry

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33 views

What are the advantages and limitations of using gel permeation chromatography for the characterization of a polymer sample?

answered Feb 13 in Polymer Chemistry

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26 views

What is the current density in an electrochemical cell where a current of 5 amperes is passed through a copper electrode with a surface area of 0.1 square meters for 10 minutes? The half-cell reaction is: Cu2+ + 2 e- -> Cu.

answered Feb 12 in ElectroChemistry

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12 views

How can the principles of medicinal chemistry be applied to design drugs that selectively target and destroy cancer cells while sparing normal healthy cells?

answered Feb 10 in Medicinal Chemistry

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32 views

How can chemistry students improve their understanding and retention of complex chemical concepts, such as the relationship between thermodynamics and kinetics in chemical reactions, and apply them to real-world scenarios?

answered Feb 5 in Chemical education

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46 views

Calculate the standard enthalpy of formation for magnesium oxide (MgO) given the standard enthalpy of formation for magnesium (Mg) is -601.8 kJ/mol and the standard enthalpy of formation for oxygen (O₂) is 0 kJ/mol.

answered Feb 3 in ThermoChemistry

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39 views

Calculate the standard enthalpy change and the standard entropy change for the reaction: 2HCl(g) + Mg(s) → MgCl2(s) + H2(g) Given the following standard enthalpy of formation values: - HCl(g) = -92.31 kJ/mol - MgCl2(s) = -641.8 kJ/mol - H2(g) = 0 kJ/mol - Mg(s) = 0 kJ/mol Also given the following standard molar entropy values:- HCl(g) = 186.9 J/Kmol - MgCl2(s) = 138.53 J/Kmol - H2(g) = 130.7 J/Kmol - Mg(s) = 32.85 J/Kmol

answered Feb 3 in Inorganic Chemistry

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66 views

What is the impact of acid rain on soil pH in a forest ecosystem and how does it affect the growth and health of trees?

answered Jan 30 in Environmental Chemistry

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54 views

How can the concentration of calcium ions in a solution be determined using ion-selective electrodes in analytical chemistry?

answered Jan 29 in Analytical Chemistry

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44 views

Calculate the enthalpy of desorption of hydrogen gas (H2) from a platinum surface, given that the temperature of the surface is 298 K and the pressure of H2 gas above the surface is 1 atm. The adsorption enthalpy of H2 on Pt is -43300 J/mol. (Assume ideal gas behavior for H2.)

answered Jan 23 in ThermoChemistry

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53 views

Calculate the enthalpy change for the isomerization reaction of butene-1 to cis-2-butene. Given that the standard enthalpy of formation for butene-1 is -19.8 kJ/mol and for cis-2-butene is -20.4 kJ/mol, and the standard enthalpy of combustion for butene-1 is -2876 kJ/mol.

answered Jan 23 in ThermoChemistry

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91 views

A chemistry student needs to determine the concentration of a sulfuric acid solution by titrating 25.0 mL of the acid with 0.1000 M sodium hydroxide. The reaction between the two substances is H2SO4 + 2NaOH → Na2SO4 + 2H2O. If it takes 35.0 mL of the sodium hydroxide solution to fully neutralize the sulfuric acid, what is the concentration of the sulfuric acid solution in moles per liter (M)?

answered Jan 22 in Chemical reactions

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67 views

A chemistry student needs to determine how the equilibrium constant (Kc) will change when the volume of the container is increased by a factor of 3 for the following reaction at a certain temperature:2NO2(g) ⇌ N2O4(g)

answered Jan 22 in Chemical equilibrium

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73 views

A chemist mixes 0.1 mol of hydrogen (H2) with 0.2 mol of nitrogen (N2) in a 2 L flask at 400°C. The reaction H2(g) + N2(g) ⇌ 2NH3(g) establishes equilibrium. Calculate the equilibrium concentrations of hydrogen, nitrogen, and ammonia if the Kc value of the reaction at this temperature is 1.5 x 10^-2.

answered Jan 22 in Chemical equilibrium

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56 views

Why did the study of phrenology fall out of favour?

answered Jan 20 in Psychology

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