The s-Block Elements - Online Test
Q1. Lithium has most negative value,its reaction with water is less vigorous than that of sodium which has the least negative E0 value among the alkali metals. The reason is
Answer : Option D
Explaination / Solution:
Li due its small size have high Lattice energy value which compensates its high ionization energy so has most negative value
Q2. When sodium is dissolved in liquid ammonia, a solution of deep blue colour is obtained. The colour of the solution is due to
Answer : Option B
Explaination / Solution:
The color of solution is due to the presence of ammoniated electron.
Q3. The alkali metals dissolve in liquid ammonia giving deep blue solutions. When they become diamagnetic, the solution turns into
Answer : Option C
Explaination / Solution:
When the solution become diamagnetic due to formation of electron cluster in which ammoniated electron with opposite spin group- it changes its color to bronze.
Q4. lithium halides are somewhat covalent because
Answer : Option D
Explaination / Solution:
Smaller is the size, greater is the polarization . so more is the covalent character.
Q5. Choose the correct trend of the melting and boiling points in the alkali metal halides, MF, MCl, MI, MBr.
Answer : Option B
Explaination / Solution:
Smaller is the size of anion less is the polarizing power of anion so greater is the ionic character hence greater will be melting point.
Q6. All alkali metal halides are soluble in water except
Answer : Option A
Explaination / Solution:
Greater the lattice energy, higher is the melting point of the MX (metal halide) and lower is its solubility
Q7. Why is paramagnetic ?
Answer : Option C
Explaination / Solution:
is a superoxide ( 3 electron species) so has one unpaired electron thus it is paramagnetic.
Q8. Alkali metal chlorides donot form hydrates except for one metal. Choose from among the options given below.
Answer : Option B
Explaination / Solution:
Lithium due to its high hydration energy(deliquescent) forms hydrate.
Q9. In the preparation of Sodium carbonate the by- product formed is:
Answer : Option D
Explaination / Solution:
is the by product.
Q10. Washing soda is
Answer : Option C
Explaination / Solution:
Washing soda is
