UNIT 5: Alkali and Alkaline Earth Metals - Online Test

Q1. The product obtained as a result of a reaction of nitrogen with CaC2 is
Answer : Option C
Explaination / Solution:




Q2. Which of the following has highest hydration energy
Answer : Option A
Explaination / Solution:

MgCl2

The order of hydration energy of alkaline earth metal is

Be2+ > Mg2+ > Ca2+ > Sr2+ > Ba2+


Q3.

Match the flame colours of the alkali and alkaline earth metal salts in the bunsen burner

(p) Sodium (1) Brick red

(q) Calcium (2) Yellow

(r) Barium (3) Violet

(s) Strontium (4) Apple green

(t) Cesium (5) Crimson red

(u) Potassium (6) Blue

Answer : Option A
Explaination / Solution:

(p) sodium –yellow (2)

(q) Calcium – Brick red (1)

(r) Barium – apple green (4)

(s) Strontium – Crimson red (5)

(t) Cesium – blue (6)

(u) Potassium – Violet (3) 


Q4. Assertion : Generally alkali and alkaline earth metals form superoxides
Reason : There is a single bond between O and O in superoxides.
Answer : Option D
Explaination / Solution:

Among alkali and alkaline earth metals,

K, Rb and Cs alone forms superoxides.

Superoxide O2 has 3 electron bond.


Q5.

Assertion : BeSO4 is soluble in water while BaSO4 is not

Reason : Hydration energy decreases down the group from Be to Ba and lattice energy remains almost constant.
Answer : Option A
Explaination / Solution:

both are true and reason is the correct explanation of assertion.

Q6. Which is the correct sequence of solubility of carbonates of alkaline earth metals ?
Answer : Option B
Explaination / Solution:

Solubility of carbonates decreases down the group and hence the correct order of solubility is,

MgCO3 > CaCO3 > SrCO3 > BaCO3


Q7. In context with beryllium, which one of the following statements is incorrect ?
Answer : Option C
Explaination / Solution:

Correct Statement: Beryllium salts are easily hydrolysed

Q8. The suspension of slaked lime in water is known as
Answer : Option C
Explaination / Solution:

Slaked lime Ca(OH)2

The suspension is called milk of lime and the clear solution is called lime water.


Q9. A colourless solid substance (A) on heating evolved CO2 and also gave a white resi-due, soluble in water. Residue also gave CO2 when treated with dilute HCl.
Answer : Option B
Explaination / Solution:




Q10. The compound (X) on heating gives a colourless gas and a residue that is dissolved in water to obtain (B). Excess of CO2 is bubbled through aqueous solution of B, C is formed. Solid (C) on heating gives back X. (B) is
Answer : Option B
Explaination / Solution: