Chemistry Multiple Choice Questions on “s-Block Elements – Group 2 Elements : Alkaline Earth Metals”.
1. Which of the following is not an alkaline earth metal?
a) beryllium
b) boron
c) aluminium
d) calcium
Answer: a
Clarification: Beryllium, belongs to the 2nd group. It is not called as an alkaline earth metal because the first element of this group that is beryllium is different from the rest of the members and it also shows a diagonal relationship with aluminium.
2. How many electrons do group 2 elements have in their S orbital of the valence shell?
a) 1
b) 2
c) 3
d) 4
Answer: b
Clarification: The alkaline earth metals have two electrons in the s-orbital of their valence shell and their general electronic configuration as represented as ns2. Similar to the alkali metals these elements compounds are predominantly ionic.
3. Which of the following order is correct with respect to the hydration enthalpy?
a) B > Mg > Ca < Sr > Ba
b) Be+2 > Mg+2 > Ca+2 > Sr+2 > Ba+2
c) B > Mg < Ca > Sr > Ba
d) B > Mg > Ca > Sr < Ba
Answer: b
Clarification: The hydration enthalpy decreases with the increase in ionic size along with the group towards down, the correct order of hydration enthalpy is given as Be+2 > Mg+2 > Ca+2 > Sr+2 > Ba+2 and the hydration enthalpies of alkaline earth metal ions are greater than the size of alkali metal ions. We can say that these are extensively hydrated than them.
4. What is the colour of barium?
a) brick red
b) crimson
c) apple green
d) blue
Answer: c
Clarification: The colours of Barium, Strontium and Calcium are Apple Green, Crimson and brick red. These are the colours of their flames, the colours occur when an electron is excited and jumps into a higher energy level and then drop back. They emit the radiation in the form of visible light.
5. Powdered beryllium burns in order to give ___________
a) barium sulphate
b) beryllium chloride
c) beryllium nitride
d) beryllium hydride
Answer: c
Clarification: We know that beryllium is kinetically inert to Oxygen and water as it forms oxide film on the surface. But whereas powdered beryllium burns brightly on ignition in the air in order to give the oxides and nitrides of beryllium.
6. Which of the following is the best route to prepare BeF2?
a) thermal decomposition of BeF2
b) thermal decomposition of beryllium
c) thermal decomposition of (NH4)2BeF4
d) thermal decomposition of Barium sulphate
Answer: c
Clarification: All the alkali Earth metals combine with halogen at elevated temperatures forming their halides, the thermal decomposition of (NH4)2BeF4, is best road and to prepare BeF2 and BeCl2 is conveniently made from the oxide.
7. Can beryllium hydride be prepared by combining with hydrogen through Heating?
a) Yes
b) No
c) Maybe
d) May not be
Answer: b
Clarification: All the alkaline earth metals (except beryllium) their hydrides can be prepared by combining with hydrogen. We can prepare beryllium hydride, through heating beryllium chloride with lithium aluminium hydride.
8. The reduction potential of alkaline earth metals is ___________ alkali metals.
a) may be equal to
b) greater than
c) less than
d) equal to
Answer: c
Clarification: Although the alkaline earth metals are reductants in nature, their reducing potential is not as greater as alkali metals. Beryllium has a negative value when compared to the other elements in its group, this is due to the large hydration energy associated with the small size of beryllium.
9. Which of the following is a component of milk of magnesia?
a) magnesium oxide
b) magnesium sulphate
c) magnesium hydroxide
d) magnesium chloride
Answer: c
Clarification: Suspension of magnesium Hydroxide in water is known as milk of magnesia and it is used as an antacid in order to treat acidity. It works as a strong base while magnesium carbonate is an ingredient and toothpaste.
10. With which of the following elements magnesium does not form an alloy?
a) manganese
b) aluminium
c) zinc
d) barium
Answer: d
Clarification: Magnesium combines with few elements like aluminium, manganese, zinc and tin in order to form a lot of magnesium aluminium alloys which are very light in mass and are used in the construction of aircraft. There are also many other uses of magnesium.