Recent questions in Chemistry

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Calculate the corrosion current density for a zinc-copper galvanic couple, with a surface area of 10 cm² each, immersed in a 0.1 M copper sulfate solution and a 0.1 M zinc sulfate solution, respectively. Given that the exchange current density for the zinc and copper electrodes are 0.0035 A/cm² and 0.1184 A/cm², respectively, What will be the corrosion rate for the zinc electrode in micrometers per year?

asked Jan 23 in ElectroChemistry by KirbyDent557 (530 points)

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Calculate the corrosion current density for a steel pipe of diameter 10 cm and length 20 m, which is exposed to a 0.1 M HCl solution. The corrosion potential of steel in the given environment is -0.5 V (SHE), the Tafel slope is 0.12 V/decade, and the temperature is 25°C. Consider the density of steel to be 7.86 g/cm³ and the flow rate of the solution to be 5 L/min.

asked Jan 23 in ElectroChemistry by GarlandSouku (510 points)

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Calculate the corrosion current density (in mA/cm²) of a silver electrode in a galvanic couple with a standard hydrogen electrode if the measured potential of the silver electrode is -0.25 V versus the standard hydrogen electrode at a temperature of 25 °C. The Tafel slope of the silver electrode is 30 mV/decade and the corrosion potential of silver in the given environment is -0.15 V.

asked Jan 23 in ElectroChemistry by MadisonJ035 (470 points)

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Calculate the corrosion current density (in mA/cm²) of a copper metal in a 3 M sulfuric acid solution at 25°C, given that the corrosion potential is -0.35 V and the Tafel constants are 120 mV/dec for the anodic reaction and 60 mV/dec for the cathodic reaction.

asked Jan 23 in ElectroChemistry by MargieSmorgo (600 points)

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Calculate the concentration of Cu2+ ions in a 0.1 M CuSO4 solution using the given standard reduction potential of Cu2+/Cu electrode and the measured cell potential. The electrode potential of the cell is 0.78 V and temperature is 25°C.

asked Jan 23 in ElectroChemistry by ELGVirgie318 (370 points)

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Calculate the concentration of Cl^- ions in a solution if the electrode potential of a Pt/AgCl electrode in the solution is measured to be +0.222 V versus the standard hydrogen electrode (SHE) at 25°C. The standard electrode potential for the reaction AgCl(s) + e^- → Ag(s) + Cl^- is +0.222 V versus SHE at 25°C. Assume the activity coefficient of Cl^- ions in the solution is equal to 1.

asked Jan 23 in ElectroChemistry by JoleenGoethe (610 points)

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Calculate the change in internal energy of a system that releases 350 J of heat to the surroundings and does 200 J of work on its surroundings?

asked Jan 23 in Physical Chemistry by RaquelGendro (430 points)

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Calculate the change in Gibbs free energy for the reaction between hydrogen gas and iodine gas that forms hydrogen iodide gas. The balanced equation is as follows:H2(g) + I2(g) → 2HI(g)Assume a temperature of 298 K and use the following standard molar free energy of formation values:∆Gf° (HI) = -17.4 kJ/mol∆Gf° (H2) = 0 kJ/mol∆Gf° (I2) = 0 kJ/mol

asked Jan 23 in Chemical thermodynamics by KevinBrazeno (350 points)

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Calculate the change in Gibbs free energy for the electrochemical reaction, given the standard reduction potentials of the reactants and products:Cu2+ (aq) + 2e- → Cu (s)E° = +0.34 VFe2+ (aq) + 2e- → Fe (s)E° = -0.44 V

asked Jan 23 in ElectroChemistry by WiltonRuatok (430 points)

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Calculate the change in entropy when 1 mole of methane gas (CH4) is burned completely in oxygen gas (O2) at constant pressure and 298 K.

asked Jan 23 in Chemical thermodynamics by MandyFinley (690 points)

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1 answer 52 views

Calculate the change in entropy when 1 mole of an ideal gas is compressed from 4 L to 1 L irreversibly at a temperature of 298 K.

asked Jan 23 in Physical Chemistry by CarrieGabel2 (510 points)

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Calculate the change in entropy of the system when 2 moles of ammonia react to form 3 moles of hydrogen gas and 1 mole of nitrogen gas. The reaction takes place at a constant temperature of 298 K and at a pressure of 1 atm. The molar entropy of each component in the reaction is given below:Ammonia: 192.5 J/K·molHydrogen gas: 130.6 J/K·molNitrogen gas: 191.6 J/K·mol

asked Jan 23 in Chemical thermodynamics by AlisonEastwo (660 points)

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1 answer 52 views

Calculate the change in entropy for the reaction: 2H2(g) + O2(g) → 2H2O(g)if the standard entropy values of H2, O2, and H2O are 130.7 J/mol*K, 205.0 J/mol*K, and 188.7 J/mol*K, respectively.

asked Jan 23 in Inorganic Chemistry by RolandoT7187 (370 points)

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Calculate the change in entropy for the combustion of methane gas (CH4) at constant pressure and temperature of 298 K. The products of the reaction are carbon dioxide gas (CO2) and water vapor (H2O). The molar entropy of CH4, CO2 and H2O at 298 K are 186.3 J/K/mol, 213.7 J/K/mol, and 188.8 J/K/mol, respectively.

asked Jan 23 in Chemical thermodynamics by TressaV9423 (210 points)

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1 answer 49 views

Calculate the change in entropy and enthalpy for the reaction of iron (III) oxide with carbon monoxide to form iron and carbon dioxide, given the following information:Fe2O3(s) + 3CO(g) → 2Fe(s) + 3CO2(g)ΔH°f (Fe2O3) = -824.2 kJ/molΔH°f (CO) = -110.5 kJ/molΔH°f (Fe) = 0 kJ/molΔH°f (CO2) = -393.5 kJ/molΔS° (Fe2O3) = 87.4 J/K molΔS° (CO) = 197.9 J/K molΔS° (Fe) = 27.3 J/K molΔS° (CO2) = 213.6 J/K mol

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

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Calculate the change in entropy (ΔS) of the following reaction at 298 K:2SO2(g) + O2(g) → 2SO3(g) Given the standard molar entropies at 298 K: ΔS°(SO2,g) = 248.2 J/Kmol ΔS°(O2,g) = 205.0 J/Kmol ΔS°(SO3,g) = 256.2 J/Kmol

asked Jan 23 in Chemical thermodynamics by JacquieElias (390 points)

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1 answer 33 views

Calculate the change in entropy (ΔS) for the reaction in which 3 moles of carbon monoxide (CO) gas is burned with excess oxygen gas to form 3 moles of carbon dioxide (CO2) gas. The reaction is carried out at constant pressure and a temperature of 298 K.

asked Jan 23 in Inorganic Chemistry by ThereseRosso (750 points)

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Calculate the change in entropy (in J/K) for the following reaction at 298 K: 2CH3OH (l) + 3O2 (g) → 2CO2 (g) + 4H2O (l) Given the following standard entropy values (in J/K): CH3OH (l): 126.6, O2 (g): 205.0, CO2 (g): 213.6, H2O (l): 69.9

asked Jan 23 in Chemical thermodynamics by DorieKyle916 (610 points)

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1 answer 45 views

Calculate the change in enthalpy for the reaction CH4 (g) + 2O2 (g) → CO2 (g) + 2H2O (l) given that the enthalpies of formation for CH4 (g), CO2 (g) and H2O (l) are -74.81 kJ/mol, -393.51 kJ/mol and -285.83 kJ/mol respectively.

asked Jan 23 in Physical Chemistry by JameyCallist (230 points)

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1 answer 47 views

Calculate the change in enthalpy for the following chemical reaction: CH4(g) + 2O2(g) -> CO2(g) + 2H2O(l) Given that the enthalpies of formation for CH4(g), CO2(g), and H2O(l) are -74.8 kJ/mol, -393.5 kJ/mol, and -285.8 kJ/mol respectively.

asked Jan 23 in Chemical reactions by CharlesMagil (290 points)

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