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What is the formal charge on the nitrogen atom (N) in the ammonium ion (NH4+)? Show your calculation steps.

asked Mar 1 in Inorganic Chemistry by TheScientist (138k points)

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How long would it take for a molecule of oxygen to diffuse through a membrane that is 2 mm thick at a given temperature and pressure? What factors affect the rate of diffusion for this particular gas?

asked Mar 1 in Physical Chemistry by TheScientist (138k points)

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What is the enthalpy change for dissolving 10 grams of sodium chloride (NaCl) in 200 mL of water at 25°C if the final temperature of the solution is 30°C? Given: the enthalpy of solution for NaCl is -3.9 kJ/mol.

asked Mar 1 in ThermoChemistry by TheScientist (138k points)

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What is the equilibrium constant for the formation of a complex ion [Fe(SCN)6]3- when mixing 0.1 M Fe(NO3)3 and 0.1 M KSCN? The absorbance of the [Fe(SCN)6]3- ion at 450 nm is found to be 0.60. Calculate the concentration of [Fe(SCN)6]3-.

asked Mar 1 in Chemical equilibrium by TheScientist (138k points)

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What is the specific surface area of a porous material if 10 mL of nitrogen gas is adsorbed at 77 K and 1 atm and the resulting monolayer thickness is 2.5 nm? The cross-sectional area of a nitrogen molecule is 0.16 nm^2.

asked Mar 1 in Surface Chemistry by TheScientist (138k points)

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What is the enthalpy change, in kilojoules per mole, when 6.0 grams of potassium chloride (KCl) is dissolved in 200.0 mL of water at 25°C? The molar heat of dissolution of KCl is -57.3 kJ/mol.

asked Mar 1 in ThermoChemistry by TheScientist (138k points)

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What is the theoretical yield of benzocaine that can be produced from 5 grams of p-aminobenzoic acid and excess ethanol in the preparation process?

asked Mar 1 in Chemical synthesis by TheScientist (138k points)

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How can we control the rate of phosphorescence decay in a particular phosphorescent material under different temperature and light intensity conditions?

asked Mar 1 in PhotoChemistry by TheScientist (138k points)

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How does the temperature affect the selectivity of a reaction involving the decomposition of hydrogen peroxide catalyzed by iodide ions?

asked Feb 28 in Chemical kinetics by TheScientist (138k points)

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What is the heat of hydration for the reaction between magnesium sulfate heptahydrate (MgSO4•7H2O) and water (H2O) when 3.50 g of MgSO4•7H2O is dissolved in 50.0 mL of water at 25 °C? The molar heat of hydration for MgSO4•7H2O is –90.39 kJ/mol.

asked Mar 1 in ThermoChemistry by TheScientist (138k points)

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What is the theoretical yield of aspirin that can be obtained from the reaction of 2.0 grams of salicylic acid and 5.0 mL of acetic anhydride? Provide your answer in grams and show your calculations.

asked Mar 1 in Chemical synthesis by TheScientist (138k points)

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What is the enthalpy change of ionization for a solution containing 0.1 mol of HCl (aq) if 20 kJ of heat is absorbed during the ionization process?

asked Mar 1 in ThermoChemistry by TheScientist (138k points)

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What surface modification techniques can be used to enhance the catalytic activity of nanoparticles for specific chemical reactions?

asked Mar 1 in Surface Chemistry by TheScientist (138k points)

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What is the exchange current density for a corroding iron electrode in a 0.1 M solution of Fe2+ ions at 25°C, given that the rate constant for the electrode reaction is 1.2 x 10^-9 cm/s and the standard reduction potential for Fe2+/Fe is -0.44 V?

asked Mar 1 in ElectroChemistry by TheScientist (138k points)

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What is the bond length between nitrogen and oxygen atoms in NO molecule? Given the bond energy of NO is 602 kJ/mol and the reduced mass of the NO molecule is 14.8 amu.

asked Mar 1 in Chemical bonding by TheScientist (138k points)

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What is the yield of 2,4-dinitrophenol obtained from the reaction of phenol and nitric acid when starting with 10 grams of phenol and 15 mL of 65% nitric acid under specific reaction conditions?

asked Mar 1 in Chemical synthesis by TheScientist (138k points)

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What is the standard enthalpy change for the reaction between copper(II) sulfate pentahydrate and ammonia to form the deep blue complex ion Cu(NH3)4(H2O)2SO4? Show all the steps involved in calculating the standard enthalpy change.

asked Mar 1 in Chemical thermodynamics by TheScientist (138k points)

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1 answer 77 views

What is the lattice energy of Calcium oxide (CaO)? Calculate the lattice energy using Born-Haber cycle and explain the factors that affect the lattice energy of CaO.

asked Mar 1 in Inorganic Chemistry by TheScientist (138k points)

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1 answer 78 views

What is the Gibbs free energy change for the electrochemical reaction involving the oxidation of copper, Cu, to copper (II) ions, Cu2+, in a solution of CuSO4 with a potential of 0.78 V at 25°C?

asked Mar 1 in ElectroChemistry by TheScientist (138k points)

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What is the Gibbs free energy change for the electrochemical reaction when a copper electrode is placed in a 1 M copper(II) sulfate solution and a standard hydrogen electrode (SHE) is placed in a 1 M hydrogen ion solution at 25°C?

asked Mar 1 in ElectroChemistry by TheScientist (138k points)

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