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Calculate the entropy change of the following reaction at 25°C and 1 atm pressure:2NH3(g) + 3Cl2(g) → N2(g) + 6HCl(g)Given the standard entropy values are:ΔS°NH3 = 192.5 J/K•molΔS°Cl2 = 223.1 J/K•molΔS°N2 = 191.6 J/K•molΔS°HCl = 186.9 J/K•mol

asked Jan 23 in Chemical thermodynamics by KatieManzi6 (1.6k points)

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Calculate the enthalpy change for the complete oxidation of 12.5 g of methane gas assuming that all the heat evolved is used to heat up 150 g of water from 25°C to 35°C. The enthalpy of formation of CH4(g) and H2O(l) are -74.8 kJ/mol and -285.8 kJ/mol, respectively.

asked Jan 23 in ThermoChemistry by KennyWenz603 (1.7k points)

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1 answer 90 views

A student wants to know how the equilibrium position of a weak acid such as acetic acid would be affected if they add more acetate ion. If the initial concentration of acetic acid is 0.1 M and initial concentration of acetate ion is 0.05 M. What will be the new concentration of acetate ion necessary to increase the pH of the solution by 0.5 units?

asked Jan 22 in Chemical equilibrium by AgustinSteed (2.2k points)

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1 answer 176 views

When did the DSM-III introduce the concept of post-traumatic stress disorder PTSD ?

asked Jan 20 in Psychology by Marietta86T (2.0k points)

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1 answer 98 views

A chemistry student needs to prepare a buffer solution with a pH of 5.2 using acetic acid (CH3COOH) and sodium acetate (NaC2H3O2). The student has 10 mL of 0.15 M acetic acid and 15 mL of 0.20 M sodium acetate. What volume of water should the student add to make the desired buffer solution?

asked Jan 22 in Chemical reactions by MindyR870320 (1.6k points)

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1 answer 90 views

A student wants to determine the mass of silver (Ag) that will be deposited on the cathode when a current of 4 A passes through a solution of silver nitrate (AgNO3) for 30 minutes. What is the mass of silver that will be deposited on the cathode? (Assume a Faraday constant of 96,485 C/mol and the atomic mass of silver is 107.87 g/mol).

asked Jan 22 in ElectroChemistry by AlfonzoGoldi (2.0k points)

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A student formed 25 grams of carbon dioxide through a chemical reaction. If the theoretical yield of carbon dioxide is 30 grams, what is the percent yield of the reaction?

asked Jan 22 in Chemical reactions by KyleSchlemme (2.1k points)

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1 answer 101 views

A chemistry student needs to determine the conditions required for a liquid mixture of water and ethanol to boil at a temperature of exactly 80°C. What is the minimum percentage of ethanol needed in the mixture and at what pressure should it be boiled in order to achieve this specific boiling point?

asked Jan 22 in Physical Chemistry by RoyalShu7550 (1.9k points)

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1 answer 64 views

Calculate the amount of heat required to melt 50 grams of ice at 0°C and convert it into liquid water at the same temperature. The enthalpy of fusion of ice is 6.01 kJ/mol.

asked Jan 23 in ThermoChemistry by LeathaOchoa (1.7k points)

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1 answer 93 views

A student needs to calculate the maximum electrical work that can be obtained from an electrochemical cell of standard hydrogen electrode (SHE) potential -0.76 V and a zinc electrode potential of -0.46 V, when 0.5 moles of zinc metal is oxidized to form zinc ions at 25 °C. Assume that the Faraday constant is 96,485 Coulombs per mole of electrons and the gas constant is 8.314 J/mole.K.

asked Jan 22 in ElectroChemistry by TrenaSee705 (1.7k points)

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1 answer 64 views

Calculate the amount of heat absorbed when 32 grams of ice at -10°C melts into water and then further heated to 35°C. (Given: Enthalpy of fusion of ice = 6.01 kJ/mol and specific heat of water = 4.18 J/g°C)

asked Jan 23 in ThermoChemistry by Beatris65S46 (1.9k points)

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1 answer 133 views

Sure, here's a question for the student to solve:How many molecules of Hydrochloric acid (HCl) are required to completely react with 5 molecules of Sodium Hydroxide (NaOH) according to the balanced chemical equation? The balanced chemical equation is: NaOH + HCl → NaCl + H2O

asked Jan 21 in Inorganic Chemistry by DaisyThwaite (1.9k points)

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1 answer 88 views

Assuming you have the equilibrium constant value for a given chemical equation, determine the concentration of products and reactants at equilibrium for the reaction: N2(g) + 3H2(g) ⇌ 2NH3(g); Kc = 6.0 x 10^2 at 500°C. If the initial concentration of N2 is 0.1 M and the initial concentration of H2 is 0.2 M, what is the concentration of NH3 at equilibrium?

asked Jan 22 in Chemical equilibrium by DeangeloMull (1.8k points)

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1 answer 100 views

A chemistry student needs to determine the pH of a solution using a pH meter. The student has to prepare a buffer solution of pH 7.0 using 0.1M acetic acid and 0.1M sodium acetate. The student is then required to measure the pH of the prepared buffer solution using a pH meter and record the observations. Finally, the student has to compare the pH value obtained by the pH meter with the calculated pH value of the prepared buffer solution and explain any deviations observed.

asked Jan 22 in Analytical Chemistry by OrenTherrien (1.8k points)

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1 answer 59 views

Calculate the enthalpy change for the combustion of 1 mole of methane gas (CH4) at standard conditions (25°C and 1 atm), given that the standard enthalpy of formation of methane is -74.87 kJ/mol and the standard enthalpy of formation of carbon dioxide (CO2) and water (H2O) are -393.51 kJ/mol and -285.83 kJ/mol, respectively.

asked Jan 23 in ThermoChemistry by LorenzaOrell (2.1k points)

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1 answer 107 views

A beaker containing 1L of water is divided into two equal compartments by a semi-permeable membrane. One side of the membrane has 1M NaCl solution and the other side is pure water. Determine the time taken for the concentration of NaCl on both sides of the membrane to become equal through diffusion. Given: Molecular weight of NaCl is 58.44 g/mol, and diffusion coefficient of NaCl in water is 1.6 x 10^-9 m^2/s.

asked Jan 22 in Physical Chemistry by WallyMackint (1.7k points)

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1 answer 94 views

What is the product formed when propene undergoes electrophilic addition reaction with hydrogen bromide (HBr)?

asked Jan 21 in Organic Chemistry by GingerJ92570 (1.6k points)

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1 answer 89 views

A student wants to electroplate a piece of copper with silver in an electrochemical cell. If a current of 0.5 A is passed through the cell for 30 minutes, what mass of silver will be deposited on the copper piece? The atomic mass of silver is 107.87 g/mol and the faraday constant is 96,485 C/mol.

asked Jan 22 in ElectroChemistry by TatianaSteil (2.3k points)

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1 answer 47 views

Calculate the exchange current density for a zinc electrode immersed in a 1.0 M solution of zinc sulfate at 25°C when the overpotential is 0.05 V. The standard reduction potential for the Zn2+/Zn couple is -0.76 V. The transfer coefficient is 0.5. Assume that the concentration of the electrolyte does not change significantly during the reaction.

asked Jan 23 in ElectroChemistry by TroyWitcher8 (2.1k points)

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1 answer 96 views

A chemistry student wants to know the equilibrium constant for the reaction between nitrogen and hydrogen to produce ammonia. If the initial concentration of nitrogen is 0.2 moles/L, the initial concentration of hydrogen is 0.1 moles/L, and the equilibrium concentration of ammonia is 0.3 moles/L, what is the equilibrium constant for this reaction?

asked Jan 22 in Chemical reactions by Georgianna53 (2.0k points)

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