Problem 135
Select the incorrect statement(s): (a) Milk of magnesia is an aqueous solution of \(\mathrm{Mg}(\mathrm{OH})_{2}\) (b) \(\mathrm{KOH}\) is a weaker base than \(\mathrm{NaOH}\) (c) \(\mathrm{CaO}_{2}\) is less stable than \(\mathrm{MgO}_{2}\) (d) \(\mathrm{Mg}^{2+}\) ions are precipitated with the addition of \(\mathrm{NH}_{4} \mathrm{OH}\) in the presence of \(\mathrm{NH}_{4} \mathrm{Cl}\)
Problem 136
Select the correct statement(s) are: (a) \(\mathrm{Na}_{2} \mathrm{CO}_{3} \cdot \mathrm{NaHCO}_{3} \cdot 2 \mathrm{H}_{2} \mathrm{O}\) is a mineral called trona. (b) \(\mathrm{Li}_{2} \mathrm{CO}_{3}\) and \(\mathrm{MgCO}_{3}\) both are thermally stable (c) \(\mathrm{Li}_{2} \mathrm{CO}_{3}\) is only sparingly soluble in water and no \(\mathrm{LiHCO}_{3}\) has been isolated. (d) \(\mathrm{K}_{2} \mathrm{CO}_{3}\) cannot be made by a method similar to the ammonia-soda process.
Problem 137
Which of the following statement(s) is/are true? (a) Stability of alkali metal peroxide increases with increase in atomic number (b) Hydration energy of \(\mathrm{AgF}\) is higher than its lattice energy (c) Anhydrous \(\mathrm{MgCl}_{2}\) cannot be prepared by direct heating of \(\mathrm{MgCl}_{2} \cdot 6 \mathrm{H}_{2} \mathrm{O}\) (d) The milk of magnesia used as antacid is chemically \(\mathrm{MgO}+\mathrm{MgCl}_{2}\)
Problem 138
Select the correct statement(s): (a) Be dissolves in alkali forming \(\left[\mathrm{Be}(\mathrm{OH})_{4}\right]^{2-}\) (b) \(\mathrm{BeF}_{2}\) forms complex ion with \(\mathrm{NaF}\) in which Be goes with cation (c) \(\mathrm{BeCO}_{3}\) is kept in the atmosphere of \(\mathrm{CO}_{2}\) since, it is least thermally stable (d) \(\mathrm{BeF}_{2}\) forms complex ion with \(\mathrm{NaF}\) in which \(\mathrm{Be}\) goes with anion.
Problem 139
The pair of compounds which cannot exist together in aqueous solution is [IIT 1992] (a) \(\mathrm{NaH}_{2} \mathrm{PO}_{4}\) and \(\mathrm{Na}_{2} \mathrm{HCO}_{3}\) (b) \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) and \(\mathrm{NaHCO}_{3}\) (c) \(\mathrm{NaOH}\) and \(\mathrm{NaH}_{2} \mathrm{PO}_{4}\) (d) \(\mathrm{NaHCO}_{3}\) and \(\mathrm{NaOH}\)
Problem 140
Nitrate of which of the following elements can be converted into their oxides on heating? (a) \(\mathrm{Na}\) (b) \(\mathrm{Li}\) (c) \(\mathrm{Mg}\) (d) \(\mathrm{Rb}\)
Problem 141
Which of the following carbonates cannot evolve \(\mathrm{CO}_{2}\) on heating? (a) \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) (b) \(\mathrm{Rb}_{2} \mathrm{CO}_{3}\) (c) \(\mathrm{Li}_{2} \mathrm{CO}_{3}\) (d) \(\mathrm{MgCO}_{3}\)
Problem 142
Sodium sulphate is soluble in water whereas barium sulphate is sparingly soluble because [IIT 1988] (a) The hydration energy of sodium sulphate is more than its lattice energy (b) The lattice energy of barium sulphate is more than its hydration energy (c) The lattice energy has no role to play in solubility (d) The hydration energy of sodium sulphate is less than its lattice energy.
Problem 143
Which of the following oxides have rock salt structure with coordination number \(6: 6\). (a) \(\mathrm{MgO}\) (b) \(\mathrm{CaO}\) (c) \(\mathrm{SrO}\) (d) \(\mathrm{B}_{2} \mathrm{O}_{3}\)
Problem 144
\(\mathrm{Mg}\) and \(\mathrm{Zn}\) have following resemblance: (a) Both of them can be used as electrodes (b) \(\mathrm{MgO}\) and \(\mathrm{ZnO}\) are amphoteric. (c) Both of them can be used to prevent corrosion (d) \(\mathrm{MgCO}_{3}, \mathrm{ZnCO}_{3}\) both on heating give their oxides.
