Recent questions in Chemistry

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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 MeredithBren (310 points)

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1 answer 57 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 MaiPorter008 (330 points)

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1 answer 74 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 QCANestor13 (370 points)

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1 answer 90 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 JarrodKnorr7 (270 points)

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1 answer 51 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 ClaireGranth (410 points)

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1 answer 69 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 KalaChatham9 (330 points)

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1 answer 82 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 SuzanneLaufe (510 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 ClemmieSprig (470 points)

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1 answer 91 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 YongChoi989 (550 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 OllieGirardi (330 points)

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1 answer 85 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 GusBeckett50 (490 points)

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1 answer 48 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 Rosalyn18824 (470 points)

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1 answer 54 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 JohnettePass (610 points)

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1 answer 53 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 Teknocepcom (660 points)

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1 answer 62 views

A chemistry student must determine the maximum work that can be done by a gas held in a container with a fixed volume and temperature. Given the number of moles of gas and the pressure inside the container, use statistical mechanics and thermodynamic ensembles to calculate the maximum work that can be extracted from the gas.

asked Jan 22 in Physical Chemistry by Alyce26J5804 (410 points)

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1 answer 66 views

A chemistry student must calculate the boiling point of a solution composed of 10 g of glucose (C6H12O6) dissolved in 100 g of water at 1 atm pressure. The boiling point elevation constant for water (Kb) is equal to 0.512°C/m, and the normal boiling point of pure water is 100°C.

asked Jan 22 in Physical Chemistry by HoseaMaltby (650 points)

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1 answer 65 views

A Chemistry student is trying to determine the effect of changing the volume on the equilibrium position of a chemical reaction at constant temperature. If the reaction is initially in equilibrium in a 1 L container with a concentration of [X] = 0.10 M and [Y] = 0.20 M, and then the volume is decreased to 0.4 L, what will be the new equilibrium concentrations of X and Y at the new volume?

asked Jan 22 in Chemical equilibrium by SilviaGirard (310 points)

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1 answer 63 views

A chemistry student is trying to determine the boiling point of a solution containing 30 grams of glucose (C6H12O6) dissolved in 100 grams of water. Given that the boiling point of pure water is 100°C and the elevation constant for water is 0.512°C/m, what is the boiling point of the solution?

asked Jan 22 in Physical Chemistry by RetaOram433 (310 points)

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1 answer 99 views

A chemistry student is studying the reaction between hydrogen gas and iodine gas to form hydrogen iodide gas. The student has collected data on the concentration of hydrogen and the rate of reaction at different times. Using the collected data, calculate the rate constant of the reaction between hydrogen and iodine gas.

asked Jan 22 in Chemical kinetics by FredComstock (410 points)

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1 answer 69 views

A chemistry student is studying the Langmuir adsorption isotherm and wants to determine the monolayer coverage of a gas adsorbed on a solid surface. The student measures the amount of gas adsorbed at various pressures and at a constant temperature of 298 K. Using the Langmuir adsorption isotherm equation, what is the monolayer coverage of the gas on the surface at this temperature?

asked Jan 22 in Surface Chemistry by ChelseyWilbu (480 points)

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