4
MCQ (Single Correct Answer)
Metal carbonates decompose on heating to give metal oxide and carbon dioxide. Which of the metal carbonates is most stable thermally?
A
$\mathrm{MgCO}_3$
B
$\mathrm{CaCO}_3$
C
$\mathrm{SrCO}_3$
D
$\mathrm{BaCO}_3$
5
MCQ (Single Correct Answer)
Which of the carbonates given below is unstable in air and is kept in $\mathrm{CO}_2$ atmosphere to avoid decomposition?
A
$\mathrm{BeCO}_3$
B
$\mathrm{MgCO}_3$
C
$\mathrm{CaCO}_3$
D
$\mathrm{BaCO}_3$
6
MCQ (Single Correct Answer)
Metals form basic hydroxides. Which of the following metal hydroxide is the least basic?
A
$\mathrm{Mg}(\mathrm{OH})_2$
B
$\mathrm{Ca}(\mathrm{OH})_2$
C
$\mathrm{Sr}(\mathrm{OH})_2$
D
$\mathrm{Ba}(\mathrm{OH})_2$
7
MCQ (Single Correct Answer)
Some of the Group 2 metal halides are covalent and soluble in organic solvents. Among the following metal halides, the one which is soluble in ethanol is
A
$\mathrm{BeCl}_2$
B
$\mathrm{MgCl}_2$
C
$\mathrm{CaCl}_2$
D
$\mathrm{SrCl}_2$
8
MCQ (Single Correct Answer)
The order of decreasing ionisation enthalpy in alkali metals is
A
$\mathrm{Na}>\mathrm{Li}>\mathrm{K}>\mathrm{Rb}$
B
$\mathrm{Rb}<\mathrm{Na}<\mathrm{K}<\mathrm{Li}$
C
$\mathrm{Li}>\mathrm{Na}>\mathrm{K}>\mathrm{Rb}$
D
$\mathrm{K}<\mathrm{Li}<\mathrm{Na}<\mathrm{Rb}$