Hot questions

0 votes

1 answer 100 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 FerminRosale (1.5k points)

0 votes

1 answer 88 views

A student needs to determine the amount of copper present in a sample of brass using coulometry. If the sample is dissolved in acid and subjected to coulometric analysis using a standard silver electrode, what is the concentration of copper (in ppm) in the brass sample?

asked Jan 22 in Analytical Chemistry by MaybellHoffm (2.2k points)

0 votes

1 answer 92 views

A chemistry student wants to determine the surface area of a metal oxide sample using the Langmuir adsorption isotherm. The student collects adsorption data at different pressures and determines the amount of gas adsorbed on the surface. The Langmuir isotherm equation used is y = Kx / (1 + Kx), where y is the fractional surface coverage, x is the pressure of the gas, and K is a constant related to the adsorption energy. The student obtains the following data:Pressure (atm) | Fractional surface coverage-------------|---------------------------

asked Jan 22 in Surface Chemistry by ElmoMcColl39 (1.7k points)

0 votes

1 answer 89 views

A student conducted an electrochemical reaction using a copper electrode to reduce a solution containing Ag+ ions. The standard reduction potential for Ag+ is 0.80 V and the standard reduction potential for Cu2+ is 0.34 V. The student measured the cell potential to be 0.62 V. Calculate the overpotential of the reaction and determine if the reduction of Ag+ occurs spontaneously.

asked Jan 22 in ElectroChemistry by HildredU3922 (1.9k points)

0 votes

1 answer 55 views

Calculate the effect of adding a buffer solution consisting of equal amounts of acetic acid (pKa = 4.76) and sodium acetate to a 0.1 M solution of acetic acid (Ka = 1.8 x 10^-5) at equilibrium. The volume of the buffer added is equal to the volume of the acetic acid solution.

asked Jan 23 in Chemical equilibrium by DeneseSteinm (1.9k points)

0 votes

1 answer 88 views

A student needs to calculate the efficiency of a voltaic cell that has a standard potential difference of 0.78 V and produces a current of 2.5 A. The cell is operated for 8 hours and consumes a total of 2400 Coulombs of charge. What is the efficiency of this electrochemical cell?

asked Jan 22 in ElectroChemistry by EdwardoO6191 (2.5k points)

0 votes

1 answer 89 views

A solution contains 0.1 M of an unknown ion X. The electrode potential of this ion X is measured to be +0.60 V versus the standard hydrogen electrode (SHE). Calculate the concentration of ion X in the solution using electrochemical methods.

asked Jan 22 in ElectroChemistry by VickeyBatema (1.9k points)

0 votes

1 answer 100 views

A 0.1 M solution of ammonia (NH3) has a pH of 11.64 at room temperature. If sodium hydroxide (NaOH) is added to this solution such that the concentration of OH- ions becomes 0.01 M, what will be the new pH of the solution? (Assume that the dissociation of water can be ignored)

asked Jan 22 in Chemical equilibrium by ElvaL9406057 (2.3k points)

+1 vote

1 answer 142 views

When can the use of negative reinforcement be problematic?

asked Jan 20 in Psychology by Linwood6326 (2.3k points)

0 votes

1 answer 128 views

A student is given the unbalanced equation for the reaction between magnesium sulfate and sodium hydroxide in aqueous solution: MgSO4 + NaOH -> Mg(OH)2 + Na2SO4. The student needs to balance the equation and determine the coefficients for each compound.

asked Jan 21 in Inorganic Chemistry by TamikaCarril (2.2k points)

0 votes

1 answer 83 views

Assuming that the concentration of Cu2+ ions in a solution is 0.25 M, the concentration of Ag+ ions in another solution is 0.50 M, and the standard reduction potential of Cu2+(aq) + 2e- → Cu(s) is +0.34 V and that of Ag+(aq) + e- → Ag(s) is +0.80 V, calculate the current density when the two solutions are separated by a salt bridge and connected by a wire.

asked Jan 22 in ElectroChemistry by MercedesLang (2.2k points)

0 votes

1 answer 97 views

A chemistry student has 10 grams of sulfur and 15 grams of oxygen. Given the balanced equation for sulfur dioxide formation, how much sulfur dioxide can they produce? Which reactant will be the limiting reactant and what is the amount of the excess reactant?

asked Jan 22 in Chemical reactions by RenateCremor (1.9k points)

0 votes

1 answer 129 views

What is the major product obtained when 1-bromopropane reacts with sodium ethoxide in ethanol? Write the reaction mechanism for the reaction and name the type of nucleophilic substitution reaction that occurs.

asked Jan 21 in Organic Chemistry by KristalDmb02 (1.6k points)

0 votes

1 answer 95 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 JaneW5862561 (1.8k points)

0 votes

1 answer 54 views

Calculate the enthalpy change (in kJ/mol) for dissolving 10 grams of NaOH in 100 mL of water at 25°C, given that the molar heat of solution for NaOH is -444.6 kJ/mol.

asked Jan 23 in ThermoChemistry by RandolphWvo (1.9k points)

0 votes

1 answer 91 views

A chemistry student wants to investigate the adsorption behavior of a gas on a solid surface. Using the Langmuir adsorption isotherm, determine the maximum adsorption capacity of the surface and the equilibrium constant, if the surface area of the solid is 10 cm$^2$ and the gas pressure is varied from 0.1 to 1 bar at a constant temperature of 298 K.

asked Jan 22 in Surface Chemistry by TinaKesler6 (1.9k points)

0 votes

1 answer 90 views

A laboratory assistant is asked to prepare a buffer solution with a pH of 7.10 using acetic acid (CH3COOH) and sodium acetate (NaCH3COO). If the laboratory assistant has 250 mL of 0.20 M acetic acid, how many grams of NaCH3COO will be needed to make the buffer solution?

asked Jan 22 in Chemical reactions by ReinaldoMunz (1.2k points)

0 votes

1 answer 129 views

What is the oxidation state of carbon in methanol?

asked Jan 21 in Organic Chemistry by BFFRachelle (1.8k points)

0 votes

1 answer 129 views

What is the balanced chemical equation for the oxidation of ethanol (C2H5OH) to acetic acid (CH3COOH) using potassium dichromate (K2Cr2O7) as the oxidizing agent in acidic medium?

asked Jan 21 in Organic Chemistry by JerroldCleve (2.0k points)

0 votes

1 answer 133 views

What is the systematic name of the following organic molecule?CH3CH2CH(CH3)CH=C(CH3)2

asked Jan 21 in Organic Chemistry by ElviaU45322 (2.2k points)

Categories