Recent questions in Chemistry

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A chemistry student needs to determine the composition of a sample that contains an unknown mixture of sodium chloride (NaCl) and potassium chloride (KCl). The student weighs 2.00 g of the mixture and dissolves it in water to obtain a solution. The student then precipitates the chloride ions from the solution with excess silver nitrate (AgNO3) to obtain 6.50 g of silver chloride (AgCl). Using mass balance calculations, determine the mass and percentage composition of the sodium chloride and potassium chloride in the mixture.

asked Jan 22 in Analytical Chemistry by LeandraBlack (390 points)

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1 answer 50 views

A chemistry student needs to determine how the equilibrium constant (Kc) will change when the volume of the container is increased by a factor of 3 for the following reaction at a certain temperature:2NO2(g) ⇌ N2O4(g)

asked Jan 22 in Chemical equilibrium by ChristyDarri (210 points)

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1 answer 58 views

A chemistry student needs to determine how the equilibrium concentration of products and reactants change when the temperature is increased in the reaction: 2 SO2 (g) + O2 (g) ⇌ 2 SO3 (g) Given the initial concentrations of 0.15 M SO2, 0.025 M O2, and 0 M SO3, and a temperature increase of 50°C, calculate the new equilibrium concentration of each compound using Le Chatelier's Principle.

asked Jan 22 in Chemical reactions by DelilaBlacke (430 points)

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1 answer 68 views

A chemistry student needs to calculate the standard enthalpy change for the combustion reaction of methane gas (CH4) at 298 K and 1 atm pressure. The equation for the reaction is:CH4(g) + 2O2(g) --> CO2(g) + 2H2O(l)Given the following standard enthalpies of formation at 298 K:ΔHf(CO2) = -393.5 kJ/molΔHf(H2O) = -285.8 kJ/molΔHf(CH4) = -74.8 kJ/molCalculate ΔHrxn, the standard enthalpy change for the combustion reaction of methane gas.

asked Jan 22 in Chemical thermodynamics by LaraKelley10 (450 points)

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1 answer 89 views

A chemistry student needs to calculate the standard enthalpy change for the combustion reaction of methane (CH4) to produce carbon dioxide (CO2) and water (H2O) at 298 K. The student is given the following information: CH4(g) + 2O2(g) → CO2(g) + 2H2O(l) ΔH°rxn = -890.4 kJ/molThe enthalpy of formation of CH4(g) and H2O(l) are -74.8 kJ/mol and -285.8 kJ/mol, respectively. Using this data, what is the standard enthalpy change for the combustion reaction of methane (CH4) to produce carbon dioxide (CO2) and water (H2O) at 298 K?

asked Jan 22 in Chemical thermodynamics by MckinleyAlba (530 points)

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1 answer 71 views

A chemistry student needs to calculate the rate constant for the following reaction: 2 H2(g) + O2(g) --> 2 H2O(g) The initial concentration of H2 is 0.45 M and the initial concentration of O2 is 0.20 M. The reaction rate is measured to be 0.75 M/s. Calculate the rate constant for the reaction.

asked Jan 22 in Chemical kinetics by LillyZpi8210 (330 points)

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1 answer 74 views

A chemistry student needs to calculate the rate constant (k) for the following first-order reaction based on the given data: The half-life of the reaction is 20 seconds when the initial concentration of reactant is 0.2M. What is the rate constant of the reaction?

asked Jan 22 in Chemical kinetics by Jodi66242236 (390 points)

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1 answer 56 views

A chemistry student needs to calculate the new value of the ionization constant (Ka) of a weak acid when the temperature is raised from 25°C to 45°C, given that the initial value of Ka is 1.8 x 10^-5 at 25°C and the enthalpy of ionization (ΔHion) is 50.2 kJ/mol.

asked Jan 22 in Chemical equilibrium by KatriceFairc (430 points)

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1 answer 73 views

A chemistry student needs to calculate the heat required to raise the temperature of 25.0 g of water from 25°C to 60°C, given that the specific heat capacity of water is 4.18 J/g°C.

asked Jan 22 in ThermoChemistry by NewtonKirch (480 points)

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1 answer 89 views

A chemistry student needs to calculate the heat of sublimation for iodine given that its enthalpy of fusion is 15.52 kJ/mol and its enthalpy of vaporization is 41.57 kJ/mol. The molar mass of iodine is 126.90 g/mol. What is the heat of sublimation for iodine in kJ/mol?

asked Jan 22 in ThermoChemistry by CorazonLaure (410 points)

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1 answer 50 views

A chemistry student needs to calculate the heat of hydration for the reaction between anhydrous magnesium chloride (MgCl2) and water (H2O) using the following data: the enthalpy change for the dissolution of anhydrous magnesium chloride in water is -63.3 kJ/mol, and the enthalpy change for the hydration of magnesium ions (Mg2+) and chloride ions (Cl-) is -192 kJ/mol and -131 kJ/mol, respectively. Calculate the overall heat of hydration (in kJ/mol) for the reaction: MgCl2(s) + 6H2O(l) → MgCl2.6H2O(s)

asked Jan 22 in ThermoChemistry by IolaMcqueen2 (430 points)

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1 answer 68 views

A chemistry student needs to calculate the equilibrium constant for the following reaction:2 H2O(g) ⇌ 2 H2(g) + O2(g)The student has the initial concentration of H2 and O2 as 0.25 M and the initial concentration of H2O as 1.00 M. After the system reaches equilibrium, the student measures the concentration of H2 as 0.10 M. Using this information, what is the value of the equilibrium constant, Kc, for the above reaction?

asked Jan 22 in Chemical reactions by DarciPok795 (330 points)

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1 answer 76 views

A chemistry student needs to calculate the equilibrium constant (Kc) for the reaction below at a certain temperature: N2(g) + 3H2(g) ⇌ 2NH3(g)Given the initial concentrations of N2, H2, and NH3 are 0.25 M, 0.1 M, and 0.1 M respectively, what is the value of Kc for this reaction at the given temperature?

asked Jan 22 in Chemical equilibrium by TiaraTraill (330 points)

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1 answer 76 views

A chemistry student needs to calculate the enthalpy of adsorption of ammonia that is adsorbed on silica gel at a temperature of 298 K. The student is provided with the following information: - The partial pressure of ammonia in the gas phase is 0.5 atm- The initial temperature of the clean silica gel is 298 K- The final temperature of the adsorbed ammonia and silica gel mixture is 306 K- The mass of ammonia adsorbed on silica gel is 0.025 grams What is the enthalpy of adsorption of ammonia on silica gel at 298 K, in kJ/mol?

asked Jan 22 in ThermoChemistry by LynetteEspin (270 points)

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1 answer 85 views

A chemistry student needs to calculate the enthalpy of adsorption for NH3 gas onto a silica gel adsorbent. The mass of silica gel used is 5.00g and the initial temperature of the system is 298K. The student also measures the equilibrium pressure of the NH3 gas at 298K to be 0.222atm. To carry out the experiment, the student passes NH3 gas over the silica gel and waits until it reaches equilibrium. The temperature of the system is then measured to be 305K. Using this information, what is the enthalpy of adsorption of NH3 onto the silica gel adsorbent in kJ/mol?

asked Jan 22 in ThermoChemistry by ChandraK0605 (410 points)

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1 answer 35 views

A chemistry student needs to calculate the density of a 25.0 mL sample of titanium (III) nitrate that has a mass of 34.6 g. The student needs to determine the density of the sample in g/mL, and also provide their answer in kg/m³.

asked Jan 22 in Inorganic Chemistry by Kerry0848578 (490 points)

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1 answer 79 views

A chemistry student needs to calculate the concentration of copper(II) ions in a 250 mL solution, given that a current of 1.5 A was applied for 60 minutes to a copper electrode in contact with the solution. The initial concentration of copper(II) ions was 0.05 M, and the Faraday constant is 96,485 C/mol. What is the final concentration of copper(II) ions in the solution?

asked Jan 22 in ElectroChemistry by AshliSiebenh (350 points)

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1 answer 47 views

A chemistry student needs to analyze the composition of a soil sample using elemental analysis. The student has to determine the percentage of carbon, nitrogen, and sulfur present in the sample. How can the student perform elemental analysis and calculate the percentage of each element in the soil sample accurately?

asked Jan 22 in Analytical Chemistry by CurtisMontal (310 points)

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1 answer 53 views

A chemistry student needs to analyze a water sample to determine the concentration of a certain contaminant. The student knows the initial concentration of the contaminant in the source water and the volume of the source water used to produce the final sample. Can the student use mass balance calculations to determine the concentration of the contaminant in the final water sample? If so, what is the concentration of the contaminant in the final sample?

asked Jan 22 in Analytical Chemistry by ShonaClowes5 (350 points)

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1 answer 52 views

A chemistry student needs to analyze a sample of a mixture that consists of anionic and cationic species. Using capillary electrophoresis, determine the presence and concentration of each species in the sample. Additionally, suggest a suitable buffer system and optimize the electrophoresis conditions for efficient separation and detection of the species.

asked Jan 22 in Analytical Chemistry by ClaribelOKan (270 points)

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