31.

A compound AB has a simple cubic structure and has molecular mass 99. Its density is 3.4 g cm-3. What will be the edge length of the unit cell?

The molecular weight of an organic compound is 58 g mol^-1. What will be the boiling point of a solution containing 48 grams of the solute in 1200 grams of water?

[K_b for water = 0.213 C kg mole^-1; Boiling point of water = 100⁰ C]

In the first order reaction,10% of the reactant is consumed in 25 minutes. Calculate:
i) The half-life period of the reaction.
ii) The time required for completing 87.5% of the reaction.

Consider the following cell reaction at 298K:

2Ag⁺ +Cd--> 2Ag +Cd²⁺

The standard reduction potentials (E0) for Ag⁺/Ag and Cd²⁺/Cd are 0.80V and -0.40 V respectively:
1) write the cell representation.
2) what will be the emf of the cell if the concentration of Cd2+ os 0.1 M and that of Ag⁺ is 0.2M?
3) Will the cell work spontaneously for the condition given in (2) above?

What is a buffer solution? How is it prepared to explain the buffer action of as basic buffer with a suitable example?

Explain the following:
i) when NaCl is added to AgNO₃ solution, a white precipitate is formed.
ii) An aqueous solution of ammonium chloride is acidic in nature.

A 0.05 M NH₄OH solution offers the resistance of 50 ohms to a conductivity cell at 298K. If the cell constant is 0.50 cm-1 and molar conductance of NH4OH at infinite dilution is 471.4 ohm^-1cm²mol^-1, calculate:

i) Specific conductance
ii) Molar conductance
iii) Degree of dissociation

Water acts as Bronsted acid as well as a Bronsted base. Give one example each to illustrate this statement.

What type of isomerism is exhibited by the following pairs of compounds:
i) [PtCl₂(NH₃)₄]Br₂ and [PtBr₂(NH₃)₄Cl₂
ii) [Cr(SCN)(H₂O)₅]²⁺ and [Cr(NCS)(H₂O)₅]²⁺

Give balanced equations for the following reaction:

i) Silver nitrate si added to the dilute solution of sodium thiosulphate.

ii) Potassium dichromate is treated with acidified ferrous sulphate solution.

iii) Phosphorus reacts with conc. sulphuric acid.