Recent questions in Chemistry

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A chemist mixes 0.1 mol of hydrogen (H2) with 0.2 mol of nitrogen (N2) in a 2 L flask at 400°C. The reaction H2(g) + N2(g) ⇌ 2NH3(g) establishes equilibrium. Calculate the equilibrium concentrations of hydrogen, nitrogen, and ammonia if the Kc value of the reaction at this temperature is 1.5 x 10^-2.

asked Jan 22 in Chemical equilibrium by ThereseRosso (130 points)

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A chemist is attempting to electroplate copper onto a steel surface using a copper sulfate solution. The standard reduction potential for this reaction is -0.34 V, but the scientist is only seeing a voltage of -0.53 V. Calculate the overpotential for this electrochemical reaction.

asked Jan 22 in ElectroChemistry by ReganPennell (510 points)

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A chemist has a sample of an unknown compound with a mass of 5.00 g. After analyzing the sample, the following results were obtained: 0.50 g of oxygen, 1.25 g of carbon, and 3.25 g of hydrogen. Calculate the molecular formula of the unknown compound using mass balance calculations.

asked Jan 22 in Analytical Chemistry by LacyEstrada1 (170 points)

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A chemist analyzed a sample of unknown substance and found that it contains 55% carbon, 9.17% of hydrogen and the rest of the mass is oxygen. What is the percentage by mass of oxygen in the sample?

asked Jan 22 in Analytical Chemistry by TomHatley066 (450 points)

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1 answer 45 views

A chemical reaction was carried out at constant temperature and pressure. The initial concentration of the reactants and products were known. After a certain amount of time, the concentration of the reactants and products were measured. Using non-equilibrium thermodynamics, calculate the magnitude and sign of the entropy change of the system during the reaction.

asked Jan 22 in Physical Chemistry by Mavis67D147 (470 points)

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1 answer 69 views

A chemical reaction of N2O4(g) ⇌ 2NO2(g) is established in a closed vessel at a certain temperature. The initial concentration of N2O4 is 0.1M. At equilibrium, the concentration of NO2 is found to be 0.6M. Calculate the equilibrium concentration of N2O4.

asked Jan 22 in Chemical equilibrium by MohamedHutch (470 points)

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1 answer 58 views

A chemical reaction is taking place where nitrogen gas and hydrogen gas are being combined to form ammonia gas. According to Le Chatelier's principle, how would increasing the pressure of the system affect the yield of ammonia gas? Provide a scientific explanation for your answer.

asked Jan 22 in Chemical reactions by DemetriaP87 (490 points)

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1 answer 78 views

A chemical plant needs to separate a mixture of benzene and toluene using a distillation column. The feed contains 40% benzene and 60% toluene. Design a distillation column to achieve a distillate with at least 90% purity of benzene. Provide the reflux ratio and the number of theoretical trays required to meet the purity specification. Assume an operating pressure of 1 atm and th

asked Jan 22 in Chemical engineering by KateBap07819 (310 points)

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1 answer 59 views

A chemical mixture containing 30% ethanol and 70% water needs to be separated using a distillation column. The feed rate is 1000 kg/hr and the desired purity for both products is 99%. The distillation column has 20 theoretical trays, and the reflux ratio is 2.5. Determine the number of trays required to achieve the desired purity for both products.

asked Jan 22 in Chemical engineering by Doris25K0972 (310 points)

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1 answer 10 views

A chemical engineering firm has been tasked with designing a chemical reactor for the synthesis of ammonia gas from nitrogen and hydrogen gases. The plant requires a production of at least 1000 kg/h of ammonia gas, and the reactor should operate at a pressure of 200 atm and a temperature of 400°C. The student should determine the optimal size and design of the reactor by considering the reaction kinetics, thermodynamics, and fluid dynamics principles. The student should also select appropriate catalysts and determine the flow rate of the reactants required to achieve the desired production rate.

asked Jan 22 in Chemical engineering by AliciaBarta8 (630 points)

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1 answer 82 views

A chemical engineering company has a mixture of ethanol and water with a concentration of 30% ethanol to separate using a distillation column. The company needs to obtain a concentration of 80% ethanol in the distillate at a reflux ratio of 3. Calculate the number of theoretical plates required in the column for the separation, assuming no vapor or liquid bypass, and that the minimum vapor velocity is maintained.

asked Jan 22 in Chemical engineering by KateNewcombe (130 points)

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1 answer 57 views

A chemical engineer wants to separate a mixture of ethanol and methanol using a distillation column. The feed to the column contains 30% ethanol and 70% methanol by mole. The engineer wants to obtain a distillate with 80% ethanol and a bottoms product containing no more than 1% ethanol. Determine the number of trays required in the distillation column to achieve this separation. Consider only equilibrium stages and assume that the feed is saturated liquid at its boiling point. The operating pressure of the column is 1 atm.

asked Jan 22 in Chemical engineering by DerrickLavin (450 points)

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1 answer 55 views

A chemical engineer needs to separate a mixture of ethanol and water using a distillation column. The feed to the column has 30 mol% ethanol and 70 mol% water, and the desired distillate composition is 95 mol% ethanol. The feed rate is 100 kmol/hour and the reflux ratio is 2. Calculate the number of theoretical trays required in the column to achieve the desired distillate composition.

asked Jan 22 in Chemical engineering by FernandoTrug (250 points)

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1 answer 67 views

A chemical engineer needs to design a distillation column for the separation of a mixture containing ethanol (boiling point of 78.4°C) and water. The desired composition of the distillate is a minimum of 90% ethanol. What is the minimum number of theoretical trays needed in the column to achieve this composition, given that the feed contains 40% ethanol and the reflux ratio is 1.5?

asked Jan 22 in Chemical engineering by WilmerHarper (530 points)

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1 answer 57 views

A certain polymerization reaction has a ΔH°rxn of -250 kJ/mol. If you need to make 500 grams of the polymer, how much energy in kilojoules will be released or absorbed during the reaction?

asked Jan 22 in ThermoChemistry by LaraKelley10 (770 points)

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1 answer 110 views

A certain metal oxide has an enthalpy of formation of -589.3 kJ/mol. When a 5.60 g sample of this oxide is reduced with excess hydrogen gas, the enthalpy change for the reaction is found to be -129.3 kJ/mol. Calculate the enthalpy of reduction per mole of this oxide.

asked Jan 22 in ThermoChemistry by RafaelaPinks (470 points)

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1 answer 51 views

A certain hydrocarbon requires 343 kJ of energy to break one mole of carbon-carbon bonds and 413 kJ/mole to break one mole of carbon-hydrogen bonds. What is the bond dissociation energy of the carbon-carbon and carbon-hydrogen bonds in this hydrocarbon?

asked Jan 22 in ThermoChemistry by LatishaKreit (450 points)

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1 answer 53 views

A certain chemical reaction has a delta H value of -120 kJ/mol. If 2.5 moles of this reactant undergo the reaction, how much energy is released or absorbed by the reaction?

asked Jan 22 in ThermoChemistry by AlfieSutton (330 points)

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1 answer 53 views

A brass alloy electrode with an area of 5 cm² is immersed in a 0.5 M NaCl solution at 25°C. Given that the standard potential of the electrode is -0.35 V versus a standard hydrogen electrode, calculate the corrosion current density of the electrode in the given environment using Tafel extrapolation.

asked Jan 22 in ElectroChemistry by OBEMelinda80 (330 points)

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1 answer 52 views

A bottle contains a mixture of nitrogen and oxygen gases. At a specific temperature and pressure, the nitrogen molecules move on an average velocity of 500 m/s and oxygen molecules move at 400 m/s. What is the partial pressure of nitrogen and oxygen in the mixture if the total pressure of the gas is 1 atm?

asked Jan 22 in Physical Chemistry by MadeleineNfh (490 points)

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