Problem 86
Based on the following reactions, arrange the metals in increasing order of their reduction potentials. $$ \mathbf{Z n}+\mathbf{C u}^{2+} \rightarrow \mathbf{Z n}^{2+}+\mathrm{Cu} ; $$ \(\mathrm{Mg}+\mathrm{Zn}^{2+} \rightarrow \mathrm{Mg}^{2+}+\mathrm{Zn}\) \(\mathrm{Cu}+2 \mathrm{Ag}^{+} \rightarrow \mathrm{Cu}^{2+}+2 \mathrm{Ag}\) (a) \(\quad \mathrm{Mg}>\mathrm{Zn}>\mathrm{Cu}>\mathrm{Ag}\) (b) \(\mathrm{Mg}<\mathrm{Zn}<\mathrm{Cu}<\mathrm{Ag}\) (d) \(\quad \mathrm{Mg}>\mathrm{Cu}>\mathrm{Zn}>\mathrm{Ag}\) (c) \(\quad \mathrm{Zn}<\mathrm{Cu}<\mathrm{Ag}<\mathrm{Mg}\)
Problem 88
If a spoon of copper metal is placed in a solution of \(\mathrm{FeSO}_{4} .\) What will be the correct observation? (a) Copper is dissolved in \(\mathrm{FeSO}_{4}\) to give brown deposit. (b) No reaction takes place. (c) Iron is deposited on copper spoon. (d) Both copper and iron are precipitated.
Problem 90
The standard \(E^{\circ}\) values of few redox couples are \(\mathrm{Zn}^{2+} / \mathrm{Zn}=-0.76 \mathrm{~V}, \mathrm{Ag}^{+} / \mathrm{Ag}=+0.80 \mathrm{~V}\) \(\mathrm{Cu}^{2+} / \mathrm{Cu}=0.34 \mathrm{~V}\). Choose the correct option. (a) Ag can oxidise \(\mathrm{Zn}\) and \(\mathrm{Cu}\). (b) \(\mathrm{Ag}\) can reduce \(\mathrm{Zn}^{2+}\) and \(\mathrm{Cu}^{2+}\). (c) Zn can reduce \(\mathrm{Ag}^{+}\)and \(\mathrm{Cu}^{2+}\). (d) Cu can reduce \(\mathrm{Zn}^{2+}\) and \(\mathrm{Ag}^{+}\).
Problem 94
A metal \(X\) displaces nickel from nickel sulphate solution but does not displace manganese from manganese sulphate solution. What is the correct order of their reducing powers? (a) \(\mathrm{Ni}>\mathrm{Mn}>X\) (b) \(X>\mathrm{Mn}>\mathrm{Ni}\) (c) \(\mathrm{Mn}>X>\mathrm{Ni}\) (d) \(\quad \mathrm{Mn}>\mathrm{Ni}>X\)
Problem 95
Given \(E_{\mathrm{Ag}^{+} / \mathrm{Ag}}^{0}=+0.80 \mathrm{~V} ; \quad E_{\mathrm{Cu}^{2+} / \mathrm{Cu}}^{\circ}=+0.34 \mathrm{~V}\) \(E_{\mathrm{Ft}^{3}+i \mathrm{Fe}^{2}}=+0.76 \mathrm{~V} ; E^{\circ} \mathrm{Ce}^{4+} / \mathrm{Ce}^{3+}=+1.60 \mathrm{~V}\) Which of the following statements is not correct? (a) \(\mathrm{Fe}^{3+}\) does not oxidise \(\mathrm{Ce}^{3+}\). (b) Cu reduces \(\mathrm{Ag}^{+}\)to \(\mathrm{Ag}\). (c) Ag will reduce \(\mathrm{Cu}^{2+}\) to \(\mathrm{Cu}\). (d) \(\mathrm{Fe}^{3+}\) reduces \(\mathrm{Cu}^{2+}\) to \(\mathrm{Cu}\).
Problem 96
Write the following ions in order of decreasing capacity to accept electrons. \(\mathrm{H}^{+}, \mathrm{Mg}^{2+}, \mathrm{K}^{+}, \mathrm{Ag}^{+}, \mathrm{Zn}^{2+}\) (a) \(\mathrm{Ag}^{+}>\mathrm{H}^{+}>\mathrm{Zn}^{2+}>\mathrm{Mg}^{2+}>\mathrm{K}^{+}\) (b) \(\mathrm{H}^{+}>\mathrm{Zn}^{2+}>\mathrm{Mg}^{2+}>\mathrm{K}^{+}>\mathrm{Ag}^{+}\) (c) \(\mathrm{K}^{+}>\mathrm{Mg}^{2+}>\mathrm{Zn}^{2+}>\mathrm{H}^{+}>\mathrm{Ag}^{+}\) (d) \(\mathrm{Mg}^{2+}>\mathrm{Zn}^{2+}>\mathrm{K}^{+}>\mathrm{Ag}^{+}>\mathrm{H}^{+}\)
Problem 97
What will be the order of decreasing reducing nature for the given metals? (a) \(\mathrm{Zn}>\mathrm{Na}>\mathrm{Fe}>\mathrm{Mg}>\mathrm{Cu}>\mathrm{Ag}\) (b) \(\mathrm{Cu}>\mathrm{Fe}>\mathrm{Mg}>\mathrm{Zn}>\mathrm{Na}>\mathrm{Ag}\) (c) \(\quad \mathrm{Ag}>\mathrm{Cu}>\mathrm{Fe}>\mathrm{Zn}>\mathrm{Mg}>\mathrm{Na}\) (d) \(\mathrm{Na}>\mathrm{Mg}>\mathrm{Zn}>\mathrm{Fe}>\mathrm{Cu}>\mathrm{Ag}\)
Problem 98
Which of the following is the strongest oxidizing agent? (a) \(\mathrm{F}_{2}\) (b) \(\mathrm{Cl}_{2}\) (c) \(\mathrm{Br}_{2}\) (d) \(\mathrm{I}_{2}\)
Problem 99
Fluorine is best oxidising agent because (a) it is most electronegative. (b) it has highest reduction potential. (c) it has highest oxidation potential. (d) it has smallest size.
