Advertisements
Advertisements
Question
How will the pH of brine (aq. \[\ce{NaCl}\] solution) be affected when it is electrolysed?
Advertisements
Solution
\[\ce{NaCl (aq) -> Na^{+} (aq) + Cl^{-} (aq)}\]
Cathode: \[\ce{H2O(l) + e^{-} -> 1/2 H2(g) + OH^{-} (aq)}\]
Anode: \[\ce{Cl^{-} (aq) -> 1/2 Cl2(g) + e^{-}}\]
Overall reaction: \[\ce{NaCl(aq) + H2O(l) -> NaOH(aq) + H2(g) + Cl2(g)}\]
\[\ce{NaOH}\] is a strong base, they turn the brine solution basic and pH will increase.
APPEARS IN
RELATED QUESTIONS
Construct a labelled diagram for the following cell:
`Zn|Zn^(2+)(1M)||H^+(1M)|H_(2(g,1atm))|Pt`
How many electrons flow through a metllic wire if a current of 0·5 A is passed for 2 hours? (Given : 1 F = 96,500 C mol−1)
Why cannot we store AgNO3 solution in copper vessel?
How many faradays of electricity are required to produce 6 g of Mg from MgCl2?
How many moles of electrons are required for reduction of 2 moles of Zn2+ to Zn?
If 'I' stands for the distance between the electrodes and 'a' stands for the area of cross-section of the electrode, `"l"/"a"` refers to ____________.
How many faradays of electricity are required for the following reaction to occur
\[\ce{MnO^-_4 -> Mn^2+}\]
A current strength of 3.86 A was passed through molten Calcium oxide for 41minutes and 40 seconds. The mass of Calcium in grams deposited at the cathode is (atomic mass of Ca is 40g/mol and 1F = 96500 C).
In the electrochemical cell: Zn|ZnSO4 (0.01 M)||CuSO4 (1.0 M)|Cu, the emf of this Daniel cell is E1. When the concentration of ZnSO4 is changed to 1.0 M and that CuSO4 changed to 0.01 M, the emf changes to E2. From the above, which one is the relationship between E1 and E2?
Describe the construction of Daniel cell. Write the cell reaction.
Why is anode in galvanic cell considered to be negative and cathode positive electrode?
Reduction potential of two metals M1 and M2 are \[\ce{E^0_{{M_1^{2+}|M_1}}}\] = −2.3 V and \[\ce{E^0_{{M_2^{2+}|M_2}}}\] = 0.2 V. Predict which one is better for coating the surface of iron.
Given: \[\ce{E^0_{{Fe^{2+}|Fe}}}\] = −0.44 V
An electrochemical cell can behave like an electrolytic cell when ______.
Match the terms given in Column I with the items given in Column II.
| Column I | Column II |
| (i) Λm | (a) intensive property |
| (ii) ECell | (b) depends on number of ions/volume |
| (iii) K | (c) extensive property |
| (iv) ∆rGCell | (d) increases with dilution |
Calculate the standard EMF ofa cell which involves the following cell reactions
\[\ce{Zn + 2 Ag+ -> Zn^{2+} + 2 Ag}\]
Given that \[\ce{E^{o}_{Zn/Zn^{2+}}}\] = 0.76 volt and \[\ce{E^{o}_{Ag/Ag^{+}}}\] = – 0.80 volt.
Which of the following statements about galvanic cell is incorrect
If 0.5 amp current is passed through acidified silver nitrate then in 100 minutes the mass of silver, deposite on cathode is (eq. wt. of silver nitrate + 108).
If the value of Ksp for Hg2Cl2 (s) is X then the value of X will be ____ where pX = - log X.
Given:
\[\ce{Hg2Cl2 + 2e- -> 2Hg(l) + 2Cl-}\], E° = 0.27 V
\[\ce{Hg+2 + 2e- -> 2Hg(l)}\] E° = 0.81 V
In a solution of CuSO4, how much time will be required to precipitate 2 g copper by 0.5 ampere current?
