When acidulated water (dil.H2SO4 solution)
Question: When acidulated water (dil.H2SO4 solution) is electrolysed, will the pH of the solution be affected? Justify your answer. Solution: Anode: 2H2O(l) O2(g) + 4H+ (aq) + 4e Cathode: 4H+ + 4e- 2H2 Overall cell reaction: 2H2O(l) O2(g) + 2H2(g) pH remains the same because concentration of H+ ions remains constant....
Read More →Solutions of two electrolytes ‘A’
Question: Solutions of two electrolytes A and B are diluted. The of B increases 1.5 times while that of A increases 25 times. Which of the two is a strong electrolyte? Justify your answer. Solution: Electrolyte B is strong as on dilution the number of ions remains the same, only interionic attraction decreases; therefore, the increase in Λm is small....
Read More →Unlike dry cell, the mercury cell has a constant
Question: Unlike dry cell, the mercury cell has a constant cell potential throughout its useful life. Why? Solution: The electrolyte is not consumed in the cell and thus the current will deliver at constant potential throughout, overall reaction contains no ions whose concentration can change over time. So, the cell potential remains constant throughout the mercury cell life....
Read More →How will the pH of brine (aq. NaCl solution)
Question: How will the pH of brine (aq. NaCl solution) be affected when it is electrolyzed? Solution: NaCl (aq)Na+ (aq) + Cl (aq) Cathode: H2O(l ) + e 1/2 H2(g) + OH (aq) Anode: Cl (aq) 1/2 Cl2(g) + e Overall reaction: NaCl(aq)+H2O(l)NaOH(aq)+H2(g)+Cl2(g) NaOH is a strong base, they turn the brine solution basic and pH will increase....
Read More →A galvanic cell has an electrical potential of 1.1V.
Question: A galvanic cell has an electrical potential of 1.1V. If an opposing potential of 1.1V is applied to this cell, what will happen to the cell reaction and current flowing through the cell? Solution: The cell reaction stops and there will be no flow of current through the cell when the opposing potential becomes equal to electrical potential. Therefore no chemical reaction takes place....
Read More →Why is alternating current used for measuring
Question: Why is alternating current used for measuring the resistance of an electrolytic solution? Solution: The alternating current keeps the concentration of ions constant whereas direct current changes the concentration of ions. That is why alternating current used for measuring the resistance of an electrolytic solution....
Read More →What is electrode potential?
Question: What is electrode potential? Solution: The potential difference developed between an electrode and electrolyte is called the electrode potential. Standard electrode potential will be always reduction potential....
Read More →Value of standard electrode potential for
Question: Value of standard electrode potential for the oxidation of Cl ions is more positive than that of water, even then in the electrolysis of aqueous sodium chloride, why is Cloxidised at anode instead of water? Solution: The oxidation of water to oxygen is kinetically unfavourable and requires excess potential called over-potential. Over-potential is the excess potential required to drive a reaction at a particular rate....
Read More →Depict the galvanic cell in
Question: Depict the galvanic cell in which the cell reaction is Cu + 2Ag+ 2Ag + Cu2+ Solution: Anode- Oxidation half-cell: Cu Cu2+ + 2e- Cathode- Reduction half-cell: 2Ag+ + 2e- 2Ag Overall reaction : Cu + 2Ag+ Cu2+ + 2Ag Cu|Cu2+(aq,1M) || Ag+(aq, 1M)| Ag...
Read More →Aqueous copper sulphate solution and aqueous
Question: Aqueous copper sulphate solution and aqueous silver nitrate solution are electrolysed by 1 ampere current for 10 minutes in separate electrolytic cells. Will, the mass of copper and silver, deposited on the cathode be the same or different? Explain your answer. Solution: W= itE/96500 = 1106031.75/96500 Equivalent mass of Cu2+ is different from the equivalent mass of Ag+ so obviously the mass of copper deposited will not be the same as the mass of silver deposited....
Read More →Mark the tick against the correct answer in the following:
Question: Mark the tick against the correct answer in the following: Let $S$ be the set of all straight lines in a plane. Let $R$ be a relation on $S$ defined by a $R$ b $\Leftrightarrow$ a $\|$ b. Then, $R$ is A. reflexive and symmetric but not transitive B. reflexive and transitive but not symmetric C. symmetric and transitive but not reflexive D. an equivalence relation Solution: According to the question , Given set $S=\{x, y, z\}$ And $R=\{(x, x),(y, y),(z, z)\}$ Formula For a relation $R$ ...
Read More →What does the negative sign in
Question: What does the negative sign in the expression EZn2+/Zn= -0.76V mean? Solution: A negative value is that hydrogen gas is more stable than the reduced form of species. Here, the reduced form (Zn) is not stable. It is difficult to reduce Zn2+ to Zn. So, the reverse is more likely to happen. Zn would rather get oxidized to Zn2+ and H+ will get reduced...
Read More →Under what condition is
Question: Under what condition is ECell = 0 or ΔrG = 0? Solution: Electrolysis happens when a redox reaction occurs. Like all reactions, redox reaction to moves towards equilibrium. At equilibrium condition, the cell has discharged completely, and cell potential drops to zero. ∆rG= -nF E cell = 0...
Read More →Evaluate the integral
Question: Evaluate the integral $\int \frac{1}{4+3 \tan x} d x$ Solution: Ideas required to solve the problems: * Integration by substitution: A change in the variable of integration often reduces an integral to one of the fundamental integration. If derivative of a function is present in an integration or if chances of its presence after few modification is possible then we apply integration by substitution method. * Knowledge of integration of fundamental functions like sin, cos, polynomial, l...
Read More →Can E°cell or ΔrG° for cell reaction
Question: Can Ecell or ΔrG for cell reaction ever be equal to zero? Solution: E Cell or ∆r G can never be equal to zero. The only standard electrode potential which is arbitrarily assigned the value zero is the standard hydrogen electrode (SHE). Since everything else is measured concerning SHE; the E cell can never be zero....
Read More →Can absolute electrode potential
Question: Can absolute electrode potential of an electrode be measured? Solution: No. It cannot be measured. We can only measure the difference in electrode potential between the two half-cells. We can also measure electrode potential difference concerning a standard electrode....
Read More →Mark the tick against the correct answer in the following:
Question: Mark the tick against the correct answer in the following: Let $S$ be the set of all straight lines in a plane. Let $R$ be a relation on $S$ defined by a $R \quad b \Leftrightarrow a \perp b$. Then, $R$ is A. reflexive but neither symmetric nor transitive B. symmetric but neither reflexive nor transitive C. transitive but neither reflexive nor symmetric D. an equivalence relation Solution: According to the question, Given set $S=\{x, y, z\}$ And $R=\{(x, y),(y, z),(x, z),(y, x),(z, y),...
Read More →For the given cell,
Question: For the given cell, Mg|Mg2+|| Cu2+|Cu (i) Mg is cathode (ii) Cu is cathode (iii) The cell reaction is Mg + Cu2+ Mg2+ + Cu (iv) Cu is the oxidising agent Solution: Option (ii)Cu is cathodeand (iii)The cell reaction is Mg + Cu2+ Mg2+ + Cu are the answers....
Read More →Molar conductivity of ionic solution
Question: Molar conductivity of ionic solution depends on ___________. (i) temperature. (ii) distance between electrodes. (iii) the concentration of electrolytes in solution. (iv) the surface area of electrodes. Solution: Option (i)temperature and (iii)the concentration of electrolytes in solution are the answers....
Read More →Mark the tick against the correct answer in the following:
Question: Mark the tick against the correct answer in the following: Let $A=\{1,2,3\}$ and let $R=\{(1,1),(2,2),(3,3),(1,2),(2,1),(2,3),(3,2)\} .$ Then, $R$ is A. reflexive and symmetric but not transitive B. symmetric and transitive but not reflexive C. reflexive and transitive but not symmetric D. an equivalence relation Solution: Given set $A=\{1,2,3\}$ And $R=\{(1,1),(2,2),(3,3),(1,2),(2,1),(2,3),(3,2)\}$ Formula For a relation $R$ in set $A$ Reflexive The relation is reflexive if $(a, a) \i...
Read More →Conductivity κ , is equal to ____________.
Question: Conductivity , is equal to ____________. (i) 1/R l/A (ii) G*/R (iii) ˄m (iv) l/A Solution: Option (i)1/R l/A and (ii)G*/R are the answers....
Read More →Mark the tick against the correct answer in the following:
Question: Mark the tick against the correct answer in the following: Let $A=\{a, b, c\}$ and let $R=\{(a, a),(a, b),(b, a)\} .$ Then, $R$ is A. reflexive and symmetric but not transitive B. reflexive and transitive but not symmetric C. symmetric and transitive but not reflexive D. an equivalence relation Solution: Given set $A=\{a, b, c\}$ And $R=\{(a, a),(a, b),(b, a)\}$ Formula For a relation $R$ in set $A$ Reflexive The relation is reflexive if $(a, a) \in R$ for every $a \in A$ Symmetric The...
Read More →Mark the tick against the correct answer in the following:
Question: Mark the tick against the correct answer in the following: Let $A=\{1,2,3\}$ and let $R=\{(1,1),(2,2),(3,3),(1,3),(3,2),(1,2)\} .$ Then, $R$ is A. reflexive and symmetric but not transitive B. reflexive and transitive but not symmetric C. symmetric and transitive but not reflexive D. an equivalence relation Solution: Given set $A=\{1,2,3\}$ And $R=\{(1,1),(2,2),(3,3),(1,3),(3,2),(1,2)\}$ Formula For a relation $R$ in set $A$ Reflexive The relation is reflexive if $(a, a) \in R$ for eve...
Read More →Evaluate the integral
Question: Evaluate the integral $\int \frac{2 \tan x+3}{3 \tan x+4} d x$ Solution: Ideas required to solve the problems: * Integration by substitution: A change in the variable of integration often reduces an integral to one of the fundamental integration. If derivative of a function is present in an integration or if chances of its presence after few modification is possible then we apply integration by substitution method. * Knowledge of integration of fundamental functions like sin, cos, poly...
Read More →What will happen during the electrolysis
Question: What will happen during the electrolysis of an aqueous solution of CuSO4 in the presence of Cu electrodes? (i) Copper will deposit at the cathode. (ii) Copper will dissolve at the anode. (iii) Oxygen will be released at anode. (iv) Copper will deposit at the anode. Solution: Option (i) and (ii) are the answers...
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