A colourless salt among the following that gives violet colour to Bunsen flame is -
1. Na2CO3
2. K2CO3
3. Cu(OH)2
4. MgCO3
A compound soluble in pyridine is:-
1. LiCl
2. CsCl
3. NaCl
4. KCl
Dissolving metallic Zn in excess of NaOH produces:-
(1) Na2ZnO2
(2) Zn(OH)2
(3) ZnO
(4) Zn(OH)2 & Na2ZnO2
Superoxide is formed on heating with an excess of air by:-
1. Li, Na
2. Mg, Be
3. Na, K
4. K, Rb
For the alkali metals, which of the following increases with increasing atomic number:-
1. Ionization potential
2. Electronegativity
3. Atomic radius
4. Hydration energy of the univalent ion
On heating Li2CO3 and Na2CO3.10H2O, residue is left after heating. The weight loss is due to
1. Evolution of CO2 from Na2CO3.10H2O only
2. Evolution of CO2 from Li2CO3 only
3. Due to evolution of CO2 from Li2CO3 and H2O from Na2CO3.10H2O
4. H2O from Na2CO3.10H2O
An ion among the following that have largest size in an aqueous solution is -
1. Rb+
2. Na+
3. K+
4. Li+
Which of the following alkali metal ion in aqueous solution is the best conductor of electricity?
(1) Li+
(2) Na+
(3) Cs+
(4) K+
Which salt will not impart color to flame?
1. LiCl
2. MgCl2
3. CaCl2
4. KI
The incorrect statement among the following is-
1. Lithium is the strongest reducing agent.
2. Density of potassium is more than sodium.
3. Cs are used in devising photoelectric cells.
4. All alkali metals give a blue solution in liquid ammonia.