Tag: physical properties of alkaline earth metals

Questions Related to physical properties of alkaline earth metals

Select the correct statement(s) about barium :

chemistry group 2 physical properties of alkaline earth metals alkali metals properties of alkaline earth metals

  1. It shows photoelectric effect.

  2. It is silvery white metal.

  3. It forms $Ba(N _3) _2$ which is used in preparation of green fire.

  4. Its ionization energy is less than radium.

Show answer
Correct Option: B,C,D
Explanation:

A) It shows photoelectric effect.False,becuase it has completely filled s orbital so removal of electron is difficult.

B) It is silvery white metal.True.

C) It forms $Ba(N _3) _2$ which is used in preparation of green fire.True.

D) Its ionization energy is less than radium True.

Hence options B,C & D are correct.

The most lightest alkaline earth metal is:

chemistry group 2 physical properties of alkaline earth metals alkali metals properties of alkaline earth metals

  1. $Be$

  2. $Mg$

  3. $Ca$

  4. $Ba$

Show answer
Correct Option: C
Explanation:

Calcium $(Z=20),$ is the lightest alkaline earth metal, with a density of $1.55 g/cm^3$, lighter than both beryllium and magnesium.

Which of the following has highest melting point?

chemistry group 2 physical properties of alkaline earth metals alkali metals properties of alkaline earth metals

  1. Magnesium

  2. Barium

  3. Calcium

  4. Beryllium

Show answer
Correct Option: D
Explanation:

Beryllium has highest melting point (1560 K).
In fact, the melting point, the boiling point and the ionisation enthalpy of beryllium are highest of all the alkaline earth metals. This is due to small atomic size of beryllium.

Select the incorrect choice: 

chemistry group 2 physical properties of alkaline earth metals alkali metals properties of alkaline earth metals

  1. the solubility of alkaline earth metal's carbonates, sulphates and chromates decreases Be to Be.

  2. the solubility of alkaline earth metal's hydroxides is less than alkali metal hydroxides.

  3. solubility of alkaline earth metal's oxides increases from Be to Ba.

  4. $SO _2$ on passing in lime water turns is milky.

Show answer
Correct Option: A

Dehydration of hydrates of halides of calcium, barium and strontium i.e., $CaCl _2.6H _2O,BaCl _2.2H _2O,SrCl _2.2H _2O$ can be achieved by heating. These become wet on keeping in the air. Which of the following statements is correct about these halides?

chemistry group 2 physical properties of alkaline earth metals alkali metals properties of alkaline earth metals

  1. The act as dehydrating agents.

  2. They can absorb moisture from air.

  3. They have tendency to from hydrate which decreases from calcium to barium.

  4. All of the above

Show answer
Correct Option: D
Explanation:

Halides of calcium, barium and strontium act as dehydrating agent as they are hygroscopic in nature. They absorb moisture. Also they have tendency to form hydrate which decreases from $Ca^{2+}$ to $Sr^{2+}$ due to increase in size and decrease in polarization power.

Which of the following metal sulphide is water soluble?

chemistry group 2 physical properties of alkaline earth metals alkali metals properties of alkaline earth metals

  1. $CaS$

  2. $ZnS$

  3. $HgS$

  4. $CdS$

Show answer
Correct Option: A
Explanation:

Calcium sulphide, $CaS$ and zinc sulphide $ZnS$ are slightly soluble in water.
Cadmium sulphide $CdS$ and mercury (II) sulfide are insoluble in water.

Which of the following does/do not impact characteristic colour to the flame?

chemistry group 2 physical properties of alkaline earth metals alkali metals properties of alkaline earth metals

  1. $MgSO _4$

  2. $CaCl _2$

  3. $Sr(NO _3) _2$

  4. $BeCl _2$

Show answer
Correct Option: A,D
Explanation:

$CaCl _2$ has orange colour.
$Sr(NO _3) _2$ has crimson colour flame.


Be and Mg do not impart any colour to the flame due to higher ionization energy and small size.The energy of the flame is not sufficient to excite the electrons to higher energy levels. Hence, they do not impart any characteristic colour to the flame

The correct increasing order of basic nature among Be, Mg, Ca and Sr is :

chemistry group 2 physical properties of alkaline earth metals alkali metals properties of alkaline earth metals

  1. $Be < Ca < Mg < Sr$

  2. $Be < Mg < Sr < Ca$

  3. $Be < Mg < Ca < Sr$

  4. $Ca < Sr < Be < Mg$

Show answer
Correct Option: C
Explanation:
The correct increasing order of basic nature among Be, Mg, Ca and Sr is $Be < Mg < Ca < Sr$.
$Be$ forms amphoteric oxides and hydroxides, whereas other alkaline earth metals form basic oxides and hydroxides. The basicity increases on moving down the group due to increase in the size of the metal ion, decrease in the ionization energy and increase in the electropositive character. This increases the polarity of metal oxygen bond and internuclear distance which in turn increases the ease of formation of ion and the basic character.

Select the correct statements :

chemistry group 2 physical properties of alkaline earth metals alkali metals properties of alkaline earth metals

  1. Solubility of alkali earth metal's oxide decreases down the group

  2. Solubility of alkaline earth metal's sulphide increases down the group

  3. Solubility of alkali metal's hydroxide increases down the group

  4. Solubility of alkali metal's fluorides increases down the group

Show answer
Correct Option: B,C,D

Select the correct order of density.

chemistry group 2 physical properties of alkaline earth metals alkali metals properties of alkaline earth metals

  1. Na > K

  2. Na < K

  3. Mg > Ca

  4. Mg < Ca

Show answer
Correct Option: A,C
Explanation:

The trend of density amongst alkali metals: $Li<K<Na<Rb<Cs$


The trend of density amongst alkaline earth metals: $Ca<Mg<Be<Sr<Ba<Ra$

Hence the correct choices are $Na>K$ and $Mg>Ca$