Recent questions in Chemistry

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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 ReginaldMeud (330 points)

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1 answer 61 views

A chemistry student needs to determine the percentage of iron (Fe) present in a given iron ore sample using gravimetric analysis. The student is provided with the mass of the iron ore sample and a standardized solution of potassium dichromate (K2Cr2O7) to use for the analysis. What is the percentage of iron (Fe) in the given iron ore sample?

asked Jan 22 in Analytical Chemistry by WilfredoHunt (530 points)

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1 answer 40 views

A chemistry student needs to determine the percentage of calcium carbonate (CaCO3) present in a mixture of calcium carbonate and calcium phosphate. The student has the following information: A 1.00-gram sample of the mixture was dissolved and reacted with excess hydrochloric acid (HCl), producing 0.236 grams of carbon dioxide (CO2) gas. The balanced chemical equation for the reaction is: CaCO3 + 2HCl → CaCl2 + CO2 + H2O. The student also knows that the molecular weight of CaCO3 is 100.09 g/mol and that of Ca3(PO4)2 is 310.18 g/mol. What is the percentage of calcium carbonate in the mixture?

asked Jan 22 in Analytical Chemistry by TanjaDoss808 (350 points)

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1 answer 61 views

A chemistry student needs to determine the percent composition of nitrogen (N) in a sample of an unknown organic compound. Using elemental analysis, the student determines the mass of the sample to be 0.254 g and the mass of the products after combustion to be 0.727 g of CO2 and 0.298 g of H2O. What is the percent composition of nitrogen in the sample?

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

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1 answer 61 views

A chemistry student needs to determine the percent by mass of magnesium (Mg) in a sample of limestone. The student has access to 5 grams of the sample and is provided with the following information: the sample is comprised of calcium carbonate (CaCO3) and magnesium carbonate (MgCO3); the atomic masses of the elements are: Ca = 40.08 g/mol, C = 12.01 g/mol, O = 16.00 g/mol, and Mg = 24.31 g/mol; and the sample contains a total of 3.06 grams of carbon (C). Calculate the percentage by mass of magnesium in the limestone sample using mass balance calculations.

asked Jan 22 in Analytical Chemistry by CeliaThomson (530 points)

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1 answer 56 views

A chemistry student needs to determine the oxidation state changes of the atoms and identify the oxidizing and reducing agents in the following reaction: C2H5OH + 2 MnO4- → 2 CH3COOH + 2 MnO2 + 4 OH-

asked Jan 22 in Organic Chemistry by WillyMais08 (410 points)

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1 answer 53 views

A chemistry student needs to determine the new equilibrium concentration of a complex ion, if the temperature is increased by 10°C from the initial temperature of 25°C, and the equilibrium constant for the reaction is 0.056. The initial concentration of the reactants are: [Fe3+] = 0.025 M, [SCN-] = 0.015 M, and [FeSCN2+] = 0.007 M.

asked Jan 22 in Chemical equilibrium by VernLaporte (290 points)

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1 answer 35 views

A chemistry student needs to determine the molar mass of aluminum chloride (AlCl3). What is the molar mass of aluminum chloride?

asked Jan 22 in Inorganic Chemistry by CorneliusEli (370 points)

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1 answer 82 views

A chemistry student needs to determine the major product(s) formed from the reaction between 1-bromo-3-methylcyclohexane and sodium ethoxide in ethanol solvent with a heat source. What are the major products formed and explain the mechanism of the reaction?

asked Jan 22 in Organic Chemistry by OmarAbrahams (490 points)

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1 answer 58 views

A chemistry student needs to determine the Langmuir constant and maximum adsorption capacity of a metal oxide nanoparticle using the Langmuir adsorption isotherm equation from experimental data obtained at different concentrations of a given adsorbate in the water. Determine the Langmuir equation parameters and plot the experimental data and the Langmuir model using a graph. Finally, interpret the results in terms of the adsorption behavior of metal oxide nanoparticle towards the selected adsorbate.

asked Jan 22 in Surface Chemistry by MaisieQ71132 (370 points)

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1 answer 69 views

A chemistry student needs to determine the equilibrium constant (Kc) for the reaction: N2(g) + 3H2(g) ⇌ 2NH3(g)At a certain temperature, 0.2 mole of nitrogen gas (N2), 0.3 mole of hydrogen gas (H2), and 0.4 mole of ammonia gas (NH3) were placed in a 1 L container. Using these initial concentrations, what is the equilibrium constant (Kc) for the reaction?

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

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1 answer 64 views

A chemistry student needs to determine the equilibrium concentrations of reactants and products for the following reaction:2 NOCl (g) ⇌ 2 NO (g) + Cl2 (g)The initial concentration of NOCl is 0.50 M and the equilibrium constant, Kc = 4.68 x 10^-3. What are the equilibrium concentrations of NO and Cl2?

asked Jan 22 in Chemical equilibrium by BeatrizWerne (170 points)

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1 answer 71 views

A chemistry student needs to determine the enthalpy of oxidation of magnesium. For this, they need to conduct an experiment in which they react 1 gram of magnesium metal with excess hydrochloric acid of 2 moles concentration. They need to measure the temperature change that occurs during the reaction, which they will use to calculate the enthalpy of oxidation of magnesium. What is the enthalpy of oxidation of magnesium according to the student's experiment?

asked Jan 22 in ThermoChemistry by Jaimie13906 (550 points)

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1 answer 68 views

A chemistry student needs to determine the enthalpy of desorption for a specific substance. The substance was adsorbed onto activated carbon in a packed bed reactor at 25°C and under a pressure of 4 bar. The adsorption process was carried out until saturation was reached. The packed bed reactor was then heated to 100°C until complete desorption. The pressure was maintained at 4 bar during the entire process. Given the initial mass of the adsorbate and the final mass of the activated carbon, calculate the enthalpy of desorption for the substance.

asked Jan 22 in ThermoChemistry by DeenaGay9005 (210 points)

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1 answer 73 views

A chemistry student needs to determine the enthalpy change for the reaction of nitrogen gas reacting with hydrogen gas to form ammonia gas, given that they have the following information:N2(g) + 3H2(g) --> 2NH3(g) ΔH1 = -92.4 kJ/mol2H2(g) + O2(g) --> 2H2O(l) ΔH2 = -572.0 kJ/molN2(g) + O2(g) --> 2NO(g) ΔH3 = +180.6 kJ/molUse Hess's law to calculate the enthalpy change for the reaction:2NH3(g) + 5O2(g) --> 2HNO3(aq) + 2H2O(l)

asked Jan 22 in Chemical reactions by BridgetMorri (410 points)

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1 answer 54 views

A chemistry student needs to determine the effect on the equilibrium position of a chemical reaction when the concentration of a reactant is decreased. The student is given the balanced equation: N₂(g) + 3H₂(g) ⇌ 2NH₃(g) + heatIf the concentration of H₂ is decreased by removing 50% of its concentration, what would be the effect on the concentration of N₂, NH₃, and the position of equilibrium?

asked Jan 22 in Chemical reactions by CharliKeesle (370 points)

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1 answer 81 views

A chemistry student needs to determine the effect of increasing the temperature on the equilibrium constant of the formation of a complex ion. Given the equation: Fe3+ + 4OH- ↔ Fe(OH)4- Kc = 2.1 x 10^-18 If the initial concentration of Fe3+ is 0.02 M and OH- is 0.1 M at 25°C, what is the new equilibrium constant at 35°C assuming the reaction is exothermic and the heat of reaction is -20 kJ/mol?

asked Jan 22 in Chemical equilibrium by MonicaTweddl (290 points)

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1 answer 68 views

A chemistry student needs to determine the effect of increasing the pressure on the equilibrium position of a reaction. Consider the following reaction at equilibrium: N2(g) + 3H2(g) ⇌ 2NH3(g) If the pressure is increased, will the reaction shift to the left or right, and in what direction will the reaction quotient, Q, shift as a result? Justify your answer using Le Chatelier's principle.

asked Jan 22 in Chemical equilibrium by JocelynSui1 (410 points)

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1 answer 71 views

A chemistry student needs to determine the effect of increasing temperature on the equilibrium position of a chemical reaction in which an exothermic reaction is taking place. Given the balanced chemical equation A + B ⇌ C + heat, the student needs to determine how the concentration of products and reactants will change as the temperature is increased, and explain the observed changes using Le Chatelier's principle.

asked Jan 22 in Chemical reactions by Justin27J42 (410 points)

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1 answer 56 views

A chemistry student needs to determine the effect of decreasing the temperature on the equilibrium position of the reaction N2(g) + 3H2(g) <-> 2NH3(g) if the initial concentrations of N2, H2 and NH3 are 0.4 M, 0.6 M, and 0.8 M respectively. How does the equilibrium concentration of NH3 change if the temperature is decreased from 400 K to 300 K, assuming constant volume and pressure?

asked Jan 22 in Chemical equilibrium by MadisonFaria (610 points)

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