Recent questions in Chemistry

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Calculate the lattice energy of calcium fluoride (CaF2) given that the lattice enthalpy of formation of Ca2+ is +178 kJ/mol, the lattice enthalpy of formation of F- is -328 kJ/mol and the distance between the Ca2+ and F- ions is 231 pm.

asked Jan 23 in Inorganic Chemistry by GiseleR2384 (470 points)

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Calculate the lattice energy of Calcium Chloride (CaCl2) using Born-Haber cycle and Hess's law, given that the following information:- Dissociation energy of Cl2 molecule is 243 kJ/mol- First ionization energy of Ca atom is 590 kJ/mol- Second ionization energy of Ca atom is 1145 kJ/mol- Electron affinity of Cl atom is -348 kJ/mol- Heat of sublimation of Ca metal is 178 kJ/mol- Bond energy of Cl-Cl molecule is 242 kJ/mol

asked Jan 23 in Inorganic Chemistry by RoyceDeMaist (980 points)

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1 answer 34 views

Calculate the lattice energy of CaCl2 given that the distance between the Ca2+ and Cl- ions in the crystal lattice is 0.231 nm and the Born-Lande equation constant is 2.21 x 10^-19 J nm.

asked Jan 23 in Inorganic Chemistry by ChelseyHenle (530 points)

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Calculate the irreversible work done by a gas expanding adiabatically from an initial volume of 1 L to a final volume of 5 L against a constant external pressure of 2 atm, assuming that the gas is initially at a temperature of 300 K and that its final temperature is 400 K.

asked Jan 23 in Physical Chemistry by GusWestover (350 points)

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Calculate the internal energy and entropy change for a gas that undergoes an isothermal expansion from 2.0 L to 3.0 L at a constant temperature of 300 K.

asked Jan 23 in Physical Chemistry by TillyLeach60 (390 points)

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1 answer 54 views

Calculate the HOMO-LUMO gap of a conjugated polymer consisting of 50 monomers, assuming that the polymer is periodic in the z-direction, using a density functional theory (DFT) program of your choice. Also, determine the absorption spectrum of the polymer in the UV-vis region, and predict its color in solution.

asked Jan 23 in Quantum Chemistry by JorgDesir647 (660 points)

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Calculate the HOMO-LUMO energy gap of a conjugated polymer with a repeating unit of poly(p-phenylene vinylene) (PPV) using quantum chemical methods (such as Density Functional Theory) and determine whether the polymer is expected to exhibit optoelectronic activity in the visible region of the electromagnetic spectrum.

asked Jan 23 in Quantum Chemistry by VeraDrew6824 (330 points)

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1 answer 48 views

Calculate the heat required to sublime 34.5 g of dry ice (solid CO2) at a constant temperature and pressure, given that the heat of sublimation of CO2 is 25.2 kJ/mol.

asked Jan 23 in ThermoChemistry by BrooksBaeza (470 points)

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1 answer 54 views

Calculate the heat required to sublime 25 grams of dry ice (CO2) at a temperature of -78.5 °C if the enthalpy of sublimation is 25.2 kJ/mol.

asked Jan 23 in ThermoChemistry by MonicaTweddl (490 points)

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1 answer 44 views

Calculate the heat required to sublime 20.0 grams of dry ice (solid carbon dioxide) at a temperature of -78.5 °C, given the heat of sublimation of CO2 is 25.2 kJ/mol.

asked Jan 23 in ThermoChemistry by FlynnO086966 (350 points)

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Calculate the heat required to sublime 10 grams of dry ice (carbon dioxide) at its melting point (-78.5°C) and convert it to a gas at its boiling point (-57°C). The heat of sublimation of carbon dioxide is 25.2 kJ/mol.

asked Jan 23 in ThermoChemistry by MeriLathrop0 (570 points)

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1 answer 48 views

Calculate the heat required to raise the temperature of a 50 g sample of water from 25°C to 85°C, given that the specific heat capacity of water is 4.184 J/g°C.

asked Jan 23 in ThermoChemistry by HarryPalacio (550 points)

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1 answer 44 views

Calculate the heat required to raise the temperature of 50 grams of water from 20°C to 80°C. The specific heat capacity of water is 4.184 J/g·°C.

asked Jan 23 in ThermoChemistry by TCALora26978 (530 points)

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1 answer 56 views

Calculate the heat required to raise the temperature of 100.0 grams of water from 25°C to 50°C if the specific heat capacity of water is 4.184 J/g°C.

asked Jan 23 in ThermoChemistry by CharoletteTo (550 points)

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1 answer 45 views

Calculate the heat released when 50 ml of 0.1 M HCl is neutralized with 50 ml of 0.1 M NaOH, assuming that the specific heat capacity of the mixture is 4.18 J/g°C and the density of the final solution is 1.0 g/mL.

asked Jan 23 in ThermoChemistry by ClariceCraig (430 points)

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1 answer 59 views

Calculate the heat released when 300 mL of water at 20°C is mixed with 200 mL of ethanol at 25°C. The specific heat capacity of water is 4.18 J/g°C, the specific heat capacity of ethanol is 2.44 J/g°C, and the heat of mixing for water and ethanol is approximately -21 kJ/mol. Assume that both water and ethanol have a density of 1 g/mL and that the final temperature of the mixture is 22°C.

asked Jan 23 in ThermoChemistry by Ursula933014 (410 points)

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1 answer 49 views

Calculate the heat released when 10.0 g of solid NaOH at 25.0°C is dissolved in 200.0 mL of water also at 25.0°C, given that the heat of crystallization of NaOH is 44.5 kJ/mol and the density of water is 1.00 g/mL.

asked Jan 23 in ThermoChemistry by KeriL9813532 (530 points)

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1 answer 49 views

Calculate the heat released when 1 mole of ethane (C2H6) is combusted in oxygen gas to form carbon dioxide and water, given the following enthalpy of combustion values: ΔH°comb(C2H6) = -1560 kJ/mol ΔH°comb(O2) = -393.5 kJ/mol ΔH°f(CO2) = -393.5 kJ/mol ΔH°f(H2O) = -285.8 kJ/mol

asked Jan 23 in ThermoChemistry by VioletLoflin (410 points)

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1 answer 53 views

Calculate the heat of sublimation of solid carbon dioxide (dry ice) given that the enthalpy of fusion of solid carbon dioxide is 8.6 kJ/mol and the enthalpy of vaporization of carbon dioxide gas is 22.8 kJ/mol. (Hint: The heat of sublimation of a substance is equal to the sum of its enthalpy of fusion and enthalpy of vaporization.)

asked Jan 23 in ThermoChemistry by MeaganSheaha (170 points)

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1 answer 57 views

Calculate the heat of sublimation of solid carbon dioxide (CO2) given that its enthalpy of fusion is 8.44 kJ/mol and its enthalpy of vaporization is 25.2 kJ/mol. The molar mass of CO2 is 44.01 g/mol.

asked Jan 23 in ThermoChemistry by Shonda63420 (470 points)

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