Problem 45
Which of the following statements is not correct 51 regarding preparation of \(\mathrm{NaOH}\) ? (a) \(\mathrm{NaOH}\) is prepared by electrolysis of sodium chloride in Castner- Kellner cell. (b) Sodium metal discharged at cathode combines 52 . with mercury to form sodium amalgam. (c) Chlorine is evolved at anode. (d) Amalgam is heated to separate \(\mathrm{Na}\) and \(\mathrm{Hg}\).
Problem 47
Baking soda is (a) \(\mathrm{NaHCO}_{3}\) (b) \(\mathrm{NaHCO}_{3}-6 \mathrm{H}_{2} \mathrm{O}\) (c) \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) (d) \(\mathrm{Na}_{2} \mathrm{CO}_{3}{ }^{-1} \mathrm{OH}_{2} \mathrm{O}\)
Problem 48
Which of the following is not a use of baking soda? (a) In medicines as antacid. (b) As a component of baking powder. (c) In removing permanent hardness of water. (d) In fire extinguishers.
Problem 53
What is the biological importance of \(\mathrm{Na}\) and \(\mathrm{K}\) ions in cell fluids like blood plasma? (a) They participate in transmission of nerve signals. (b) They regulate the number of red and white blood corpuscles in the cell. (c) They can be present in any amount in the blood since they are absorbed by the cells. (d) They regulate the viscosity and colour of the blood.
Problem 56
The decreasing order of the second ionization potential of \(\mathrm{Mg}, \mathrm{Ca}\) and \(\mathrm{Ba}\) is(a) \(\mathrm{Mg}>\mathrm{Ca}>\mathrm{Ba}\) (b) \(\mathrm{Ca}>\mathrm{Ba}>\mathrm{Mg}\) (c) \(\mathrm{Ba}>\mathrm{Mg}>\mathrm{Ca}\) (d) \(\mathrm{Mg}>\mathrm{Ba}>\mathrm{Ca}\)
Problem 57
The first ionisation enthalpies of the alkaline earth metals are higher than that of alkali metals but second ionisation enthalpies are smaller, why? (a) In alkali metals, second ionisation enthalpy involves removal of electron from noble gas electronic configuration while in alkaline earth metals, second electron is removed from \(n s^{2}\) configuration. (b) Alkaline earth metals have very high melting point as compared to alkali metals. (c) Electrons in s-orbital are more closely packed in alkaline earth metals than alkali metals. (d) Due to smaller size alkaline earth metals do not form divalent ions very easily.
Problem 58
Match the column I with column II and mark the appropriate choice. \begin{tabular}{|l|l|l|l|} \hline \multicolumn{2}{|c|} { Column I } & \multicolumn{2}{c|} { Columi II = } \\\ \hline (A) & \(\mathrm{Na}\) & (i) & Crimson red \\ \hline (B) & \(\mathrm{K}\) & (ii) & Yellow \\ \hline (C) & \(\mathrm{Sr}\) & (iii) & Apple green \\ \hline (D) & \(\mathrm{Ba}\) & (iv) & Violet \\ \hline \end{tabular} (a) (A) \(\rightarrow(i),(B) \rightarrow(i i),(C) \rightarrow(i i i),(D) \rightarrow\) (iv) (b) \((\mathrm{A}) \rightarrow(\mathrm{ii}),(\mathrm{B}) \rightarrow(\mathrm{iv}),(\mathrm{C}) \rightarrow(\mathrm{i}),(\mathrm{D}) \rightarrow\) (iii) (c) \((\mathrm{A}) \rightarrow(\mathrm{iv}),(\mathrm{B}) \rightarrow\) (iii), (C) \(\rightarrow\) (ii), (D) \(\rightarrow\) (i) (d) (A) \(\rightarrow\) (iii), (B) \(\rightarrow\) (iv), (C) \(\rightarrow\) (i), (D) \(\rightarrow\) (ii)
Problem 60
Which among the following is kinetically inert towards water? (a) \(\mathrm{Na}\) (b) Be (c) \(\mathrm{Ca}\) (d) \(\mathbf{K}\)
Problem 61
An oxide of allkaline earth metals \((X)\) reacts with \(\mathrm{C}\) and \(\mathrm{Cl}_{2}\) to give a compound \(Y . Y\) is found in polymeric chain structure and is electron deficient molecule. The compound \(Y\) is (a) \(\mathrm{BeO}\) (b) \(\mathrm{BeCl}_{2}\) (c) \(\mathrm{Be}(\mathrm{OH})_{2}\) (d) \(\mathrm{BeCO}_{3}\)
Problem 63
Which of the following statements is correct regarding alkaline earth metals? (a) Alkaline earth metals are weaker reducing agents than alkali metals. (b) Alloline earth metal salts are paramagnetic in nature. (c) Alkaline earth metal salts are more soluble than corresponding alkali metal salts. (d) Solubility of sulphates of alkaline earth metals increases from top to bottom in the group.
