Recent questions in ThermoChemistry

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Calculate the amount of heat absorbed or released when 50 grams of NaCl crystals at 25°C are dissolved in 200 grams of water at the same temperature. Given the enthalpy of crystallization of NaCl is -787 kJ/mol and the specific heat capacity of water is 4.18 J/g°C.

asked Jan 23 in ThermoChemistry by JaniChewning (450 points)

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Calculate the amount of heat absorbed or released when 20 grams of dry ice (solid carbon dioxide) is converted to gaseous carbon dioxide at -78.5°C and atmospheric pressure, given the heat of sublimation of dry ice is 25.2 kJ/mol.

asked Jan 23 in ThermoChemistry by JulioStilwel (510 points)

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Calculate the amount of heat absorbed or released when 2.5 moles of sodium acetate (NaCH3COO) is crystallized from its solution at a constant temperature of 25°C. The heat of crystallization for sodium acetate is -427 kJ/mol.

asked Jan 23 in ThermoChemistry by AugustinaPal (330 points)

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Calculate the amount of heat absorbed by 50 grams of water during the process of crystallization when it is cooled from 70°C to 0°C and solidifies into ice with a heat of crystallization of 333.55 J/g.

asked Jan 23 in ThermoChemistry by AleishaHuman (300 points)

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1 answer 45 views

Calculate the amount of heat absorbed (in joules) when 10 grams of sodium hydroxide (NaOH) is dissolved in 100 mL of water at 25°C, given that the enthalpy of solution for NaOH is -44.51 kilojoules per mole.

asked Jan 23 in ThermoChemistry by Zack25G18861 (510 points)

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Calculate the amount of heat (in joules) released when 50 ml of 0.1 M hydrochloric acid (HCl) is mixed with 50 ml of 0.1 M sodium hydroxide (NaOH) at a constant pressure and a temperature of 25°C. The heat of neutralization of HCl and NaOH is -57.1 kJ/mol.

asked Jan 23 in ThermoChemistry by MelvinSimos (410 points)

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1 answer 44 views

Calculate the amount of energy required to vaporize 100 grams of liquid water at its boiling point (100°C) given its enthalpy of vaporization is 40.7 kJ/mol.

asked Jan 23 in ThermoChemistry by Shirley00407 (510 points)

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1 answer 51 views

Calculate the amount of energy required to melt 50 grams of ice at 0°C, given the enthalpy of fusion for water is 6.01 kJ/mol.

asked Jan 23 in ThermoChemistry by Kami22A8614 (310 points)

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Calculate the amount of energy required to completely desorb 2 moles of hydrogen molecules from a metal surface if the enthalpy of desorption for each H2 molecule is 436 kJ/mol.

asked Jan 23 in ThermoChemistry by RebeccaCnk8 (250 points)

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Calculate the amount of energy needed to desorb 10 moles of hydrogen gas from a metal surface, given that the enthalpy of desorption is -120 kJ/mol.

asked Jan 23 in ThermoChemistry by JannaFarmer0 (390 points)

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1 answer 56 views

Calculate the amount of energy in Joules required to melt 15 grams of ice at 0°C, given that the heat of fusion of water is 334 J/g.

asked Jan 23 in ThermoChemistry by LaunaGoodman (190 points)

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1 answer 46 views

Assuming standard conditions, calculate the standard enthalpy of combustion of methane (CH4), given that the standard enthalpies of formation of CH4 and H2O are -74.8 kJ/mol and -285.8 kJ/mol, respectively. The balanced chemical equation for the combustion of CH4 is:CH4(g) + 2O2(g) → CO2(g) + 2H2O(l) What is the standard enthalpy change (ΔH°) for this reaction?

asked Jan 22 in ThermoChemistry by TriciaMccomb (430 points)

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1 answer 7 views

Assuming complete combustion, what is the amount of heat energy released when 25 grams of methane (CH4) is burned completely in oxygen gas (O2)? The enthalpy of combustion for methane is -890.4 kJ/mol.

asked Jan 22 in ThermoChemistry by TeriBeeton0 (410 points)

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1 answer 59 views

A student wants to synthesize a polymer using the monomer vinyl chloride. The reaction is exothermic and produces a polymer with an average molecular weight of 50,000 g/mol. The enthalpy change of polymerization for this reaction is -121.8 kJ/mol. How much heat is liberated during the polymerization of 1 mol of vinyl chloride?

asked Jan 22 in ThermoChemistry by AlannahArand (310 points)

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1 answer 60 views

A student wants to prepare polyethylene using the radical polymerization process. The monomer used is ethylene, and the reaction occurs at a temperature of 60°C. The initiator used is benzoyl peroxide. The student wants to know the enthalpy change that occurs during the polymerization process. How can the student calculate the enthalpy of polymerization using the given information?

asked Jan 22 in ThermoChemistry by ShaniThrashe (430 points)

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1 answer 88 views

A student wants to measure the heat of crystallization of sodium acetate trihydrate. The student takes 50 g of sodium acetate trihydrate and dissolves it in 100 ml of water at 70°C. The solution is then allowed to cool to 20°C, during which the sodium acetate trihydrate crystallizes out. The student measures the temperature change during this process and finds that the temperature drops to 45°C. What is the heat of crystallization of sodium acetate trihydrate in kJ/mol?

asked Jan 22 in ThermoChemistry by GloriaTerpst (350 points)

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1 answer 46 views

A student wants to determine the enthalpy of combustion of octane. They measured the temperature change of 200 mL of water in a calorimeter when 1.50 grams of octane was burned completely. The initial temperature of the water was 25.0 °C and it reached a maximum of 45.0 °C. What is the enthalpy of combustion of octane?

asked Jan 22 in ThermoChemistry by Rex516068171 (390 points)

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1 answer 71 views

A student needs to prepare a solution containing 50 g of ethanol (C2H5OH) dissolved in 250 g of water (H2O) at 25°C. Assuming the heat of mixing for ethanol and water is -5.02 kJ/mol, calculate the heat released or absorbed when the two substances are mixed. Express your answer in kJ.

asked Jan 22 in ThermoChemistry by JerriPadilla (550 points)

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0 answers 79 views

A student needs to prepare a solution containing 50 g of ethanol (C2H5OH) dissolved in 250 g of water (H2O) at 25°C. Assuming the heat of mixing for ethanol and water is -5.02 kJ/mol, calculate the heat released or absorbed when the two substances are mixed. Express your answer in kJ.

asked Jan 22 in ThermoChemistry by BeulahMcclan (550 points)

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1 answer 64 views

A student needs to find the enthalpy of polymerization of ethylene from the enthalpies of combustion of ethylene gas (-1411 kJ/mol) and polyethylene (-5120 kJ/mol). Calculate the enthalpy change, in kJ/mol, for the polymerization of ethylene gas to form polyethylene.

asked Jan 22 in ThermoChemistry by ChunComeaux (710 points)

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