Chapter 10

State which one is homogeneous or heterogeneous? (a) \(\quad \overline{\text { C }_{\text {Diamond }}} \rightleftharpoons \bar{C}_{\text {graphite }}\) (b) \(\mathrm{H}_{2} \mathrm{O}_{(\mathrm{s})}=\mathrm{H}_{2} \mathrm{O}_{(\mathrm{l})}\) (c) \(\mathrm{N}_{2(\mathrm{~g})}+3 \mathrm{H}_{2(\mathrm{~g})} \rightleftharpoons 2 \mathrm{NH}_{3(\mathrm{~g})}\) (d) \(\quad \mathrm{MgCO}_{3(\mathrm{~s})} \rightleftharpoons \mathrm{MgO}_{(\mathrm{s})}+\mathrm{CO}_{2(\mathrm{~g})}\) (e) \(\mathrm{PCl}_{3(\mathrm{~g})}+\mathrm{Cl}_{2(\mathrm{~g})}=\mathrm{PCl}_{5(\mathrm{~g})}\)

Calculate the number \((n)\) of atoms contained within (a) cubic cell, (b) a body centred cubic cell, (c) a face centred cubic cell.

Write euilibrium constant for the each : (a) \(\quad \mathrm{N}_{2} \mathrm{O}_{4(\mathrm{~g})} \rightleftharpoons 2 \mathrm{NO}_{2(\mathrm{~g})}\) (b) \(\quad \mathrm{KClO}_{3(\mathrm{~s})} \rightleftharpoons \mathrm{KCl}_{(\mathrm{s})}+(3 / 2) \mathrm{O}_{2(\mathrm{~g})}\) (c) \(\mathrm{CaC}_{2(\mathrm{~s})}+5 \mathrm{O}_{2(\mathrm{~g})} \rightleftharpoons 2 \mathrm{CaCO}_{3(\mathrm{~s})}+2 \mathrm{CO}_{2(\mathrm{~g})}\) (d) \(\mathrm{N}_{2(\mathrm{~g})}+3 \mathrm{H}_{2(\mathrm{~g})} \rightleftharpoons 2 \mathrm{NH}_{3(\mathrm{~g})}\) (e)Fe \(^{3+}{ }_{\text {(aq })}+\mathrm{SCN}_{\text {(aq.) }}^{*}=\mathrm{Fe}(\mathrm{SCN})^{2+}{ }_{\text {(aq })}\) (f) \(\mathrm{CuSO}_{4} \cdot 5 \mathrm{H}_{2} \mathrm{O}_{(\mathrm{s})} \rightleftharpoons \mathrm{CuSO}_{4(\mathrm{~s})}+5 \mathrm{H}_{2} \mathrm{O}_{(\mathrm{v})}\)

A compound formed by elements \(A\) and \(B\) crystallizes in cubic structure where \(A\) atoms are at the corners of a cube and \(B\) atoms are at the face centre. What is the formula of the compound?

At room temperature, sodium crystallizes in a body centred cubic lattice with \(a=4.24 \AA\). Calculate theoretical density of sodium (At. wt. of \(\mathrm{Na}=23\) ).

The equilibrium constant of the reaction; \(\mathrm{SO}_{3(\mathrm{~g})} \rightleftharpoons \mathrm{SO}_{2(\mathrm{~g})}+1 / 2 \mathrm{O}_{2(\mathrm{~g})}\); is \(0.20 \mathrm{~mole}^{1 / 2}\) litre \(^{-1 / 2}\) at \(1000 \mathrm{~K}\). Calculate equilibrium constant for $$ 2 \mathrm{SO}_{2(\mathrm{~g})}+\mathrm{O}_{2(\mathrm{~g})}=2 \mathrm{SO}_{3(\mathrm{~g})} $$

Sodium metal crystallizes in a body centred cubic lattice with the cell edge \(a=4.29 \AA\). What is the radius of sodium atom?

Silver crystallizes in f.c.c. lattice. If edge length of the cell is \(4.077 \times 10^{-8} \mathrm{~cm}\) and density is \(10.5 \mathrm{~g} \mathrm{~cm}^{-1}\), calculate the atomic mass of silver.

For the reaction; \(\mathrm{N}_{2 \mathrm{k} \mathrm{g}}+3 \mathrm{H}_{2(\mathrm{~g})} \rightleftharpoons 2 \mathrm{NH}_{3(\mathrm{~g})}\) At \(400 \mathrm{~K}, K_{\mathrm{p}}=41 \mathrm{~atm}^{-2}\). Find the value of \(K_{\mathrm{p}}\) for each of the following reactions at the same temperature: (i) \(2 \mathrm{NH}_{3(\mathrm{~g})} \Longrightarrow \mathrm{N}_{2(\mathrm{~g})}+3 \mathrm{H}_{2(\mathrm{~g})}\) (ii) \({ }_{2} \mathrm{~N}_{2(\mathrm{~g})}+\frac{3}{2} \mathrm{H}_{2(g)} \Longrightarrow \mathrm{NH}_{3(\mathrm{~g})}\); (iii) \(2 \mathrm{~N}_{2(\mathrm{~g})}+6 \mathrm{H}_{2(\mathrm{~g})} \rightleftharpoons 4 \mathrm{NH}_{3(\mathrm{~g})}\)

Equilibrium constant, \(\mathrm{K}_{\mathrm{c}}\) for the reaction, \(\mathrm{N}_{2(\mathrm{~g})}+3 \mathrm{H}_{2(\mathrm{~g})} \rightleftharpoons 2 \mathrm{NH}_{3(\mathrm{~g})}\); at \(500 \mathrm{~K}\) is \(0.061\) litre \({ }^{2} \mathrm{~mole}^{-2} .\) At a particular time, the analysis shows that composition of the reaction mixture is \(3.00\) mol litre \(^{-1} \cdot \mathrm{N}_{2}, 2.00\) mol litre \(^{-} \mathrm{H}_{2}\), and \(0.500\) mol litre \(^{-1} \mathrm{NH}_{3} .\) Is the reaction at equilibrium? If not, in which direction does the reaction tend to proceed to reach equilibrium?