Electrochemistry and Solutions

In conductometric titration of HCl against NaOH, at the equivalence point (B) and beyond, the solution contains Na+ and Cl- ions (from the neutralization reaction) and excess OH- ions. The conductance at B is primarily due to Na+ and Cl- ions present as products of the neutralization. Initially, H+ and Cl- contribute; after neutralization, Na+ and Cl- remain.

It is Mohr's salt.

Molecular formula of Glauber’s salt is Na₂SO₄.10.H₂O. Dissolving salt cake (Na₂SO₄) in water and crystallisation at 32 ^oC yields Glauber’s salt.

The initial solubility is due to the hydrated salt. Below 305K, Na₂SO₄.10H₂O crystalises out. Above 305K the anhydrous salt separates out due to its negative temperature co-efficient of solubility.

In the formula for aluminium chloride Al_aCl_b, the respective values of a and b are 1 and 3 (i.e. AlCl₃).

The solution in bottle A is acidic and the solution in bottle B is basic. Both acids and bases dissociate into ions in water. So, both the solutions conduct electricity when an electric current is passed through them.

This option is correct and can be explained as follows: When NaCl(s) is added to the system it dissociates as NaCl(s)  ⇌  Na⁺(aq)  +  Cl^-(aq)The Cl^- ions obtained from the dissociation of solid NaCl will combine with Ag⁺ ions to precipitate AgCl. Hence the equilibrium will be shifted in forward direction in accordance with Le-Chatelier's principle and more Ag⁺ and SO₄^2- ions will be formed resulting in consumption of Ag₂SO₄ and hence its concentration will decrease.

The required reaction is, MnO₄^– +  8H⁺ +5e  →  Mn²⁺ + 4H₂O Cu⁺ – e → Cu²⁺ S^2– – 6e → S⁴⁺ Therefore, eq. wt. of Cu₂S = (M1 / ((1*2) + 6)) = M1 / 8 Hence, this is a correct option.  

A glass electrode is a type of ion-selective electrode made of a doped glass membrane that is sensitive to a specific ion. It is an important part of the instrumentation for chemical analysis and physico-chemical studies.

A fluoride selective electrode is a type of ion selective electrode sensitive to the concentration of the fluoride ion. A common example is the lanthanum fluoride electrode.

Mercury(I) chloride is also known as calomel. This dense white or yellowish-white, odourless solid is the principal example of a mercury(I) compound. It is a component of reference electrodes in electrochemistry.

The nickel-iron battery (NiFe battery) is a storage battery having a nickel(III) oxide-hydroxide cathode and an iron anode, with an electrolyte of potassium hydroxide. The active materials are held in nickel-plated steel tubes or perforated pockets.

A water-activated battery is a disposable reserve battery that does not contain an electrolyte and hence produces no voltage until it is soaked in water for several minutes.

Lithium tetrachloroaluminate is an inorganic compound, a tetrachloroaluminate of lithium, with the formula LiAlCl₄. Solution of lithium tetrachloroaluminate in thionyl chloride is the liquid cathode and electrolyte of some lithium batteries, e.g. lithium-thionyl chloride cell.

Number of ionisable chloride ions in complex [Cr(H₂O)₅Cl]Cl₂ = 2 Millimoles = Molarity x Volume (mL) x 2 = 0.02 x 30 x 2 = 1.2 Therefore, required Ag⁺ ions = 1.2 millimoles According to Millimoles = Molarity x V (mL) 1.2 = 0.2 x VV = 6 mL