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One ecologically important equilibrium is that between carbonate and hydrogencarbonate (bicarbonate) ions in natural water. (a) The standard Gibbs energies of formation of CO32−(aq) and HCO3−(aq) are −527.81 kJ mol−1 and −586.77 kJ mol−1, respectively. What is the standard potential of the HCO3−/CO32−,H2 couple? (b) Calculate the standard potential of a cell in which the cell reaction is Na2CO3(aq) + H2O(l) → NaHCO3(aq) + NaOH(aq). (c)Write the Nernst equation for the cell, and (d) predict and calculate the change in cell potential when the pH is changed to 7.0 at 298 K.
A fuel cell is constructed in which both electrodes make use of the oxidation of methane. The left-hand electrode makes use of the complete oxidation of methane to carbon dioxide and liquid water; the right-hand electrode makes use of the partial oxidation of methane to carbon monoxide and liquid water. (a) Which electrode is the cathode? (b) What is the cell potential at 25 °C when all gases are at 1 bar?
Tabulated thermodynamic data can be used to predict the standard potential of a cell even if it cannot be measured directly. The standard Gibbs energy of the reaction K2CrO4(aq) + 2 Ag(s) + 2 FeCl3(aq) → Ag2CrO4(s) + 2 FeCl2(aq) + 2 KCl(aq) is −62.5 kJ mol−1 at 298 K. (a) Calculate the standard potential of the corresponding galvanic cell and (b) the standard potential of the Ag2CrO4/Ag,CrO42− couple.
Use the information in the Resource section to calculate the standard potential of the cell Ag(s)|AgNO3(aq)||Cu(NO3)2(aq)|Cu(s) and the standard Gibbs energy and enthalpy of the cell reaction at 25 °C. (ii) Estimate the value of ΔrG⦵ at 35 °C.
Calculate the standard potential of the cell Pt(s)|cystine(aq),
cysteine(aq)|| H+(aq)|O2(g)|Pt(s) and the standard Gibbs energy of the cell reaction at 25 °C. Use E⦵ = −0.34 V for cystine(aq) + 2 H+(aq) + 2 e− → 2 cysteine(aq).
Number of ways an animal can travel from A to C via B, if there are 3 routes from A to B and 5 routes from B to C
A group of students got the following scores in a test; 5, 10, 15, and 25. Consider samples of size 2 that can be selected from the population. What is the mean of the population?
Given the overall equation for respiration (C6H12O6 + 6O2 6CO2 + 6H2O), in which step(s) in the respiratory pathway is/are each of the reactants used up and each of the products made?
(a) Mendel did not know of the existence of chromosomes. Had he known, what change might he have made in his Principle of Independent Assortment?
(b) Consider 4 different genes represented by a, b, c, d. If a is linked to b, and b to c, and c to d, does it follow that a recombination experiment would detect linkage between a and d? Explain.
A phenotypically wild-type female fruit fly that was heterozygous for genes controlling body color and wing length was crossed to a homozygous mutant male with black body (allele b) and vestigial wings (allele vg). The cross produced the following progeny: gray body, normal wings 126; gray body, vestigial wings 24; black body, normal wings 26; black body, vestigial wings 124. Do these data indicate linkage between the genes for body color and wing length? What is the frequency of recombination?
#339914 on Dec 2023