Alkali metals

Alkali metals are those elements which belong to group 1 of the modern periodic table.They have one valence electron and that electron enters the s orbital of the ultimate shell.Now let's try out some multiple choice questions regarding them:

1) Which of the following does not belong to the class of alkali metals?

    a) Li

    b) Na

    c) H

    d) K

2) The hydroxides formed by group 1 elements on reaction with water are :

    a) Acidic

    b) Alkaline

    c) Amphoteric

    d) Neutral 

3) Fr-223 has a half-life of :

    a) 11 min.

    b) 21 min.

    c) 31 min.

    d) 41 min.

4) Which of the following element among alkali metals show anomalous behaviour?

    a) Na

    b) K

    c) Fr

    d) Li

5) Among the alkali metal ions,which one has the largest hydration enthalpy?

    a) Li+

    b) Na+

    c) K+

    d) Rb+    

6) The density of K is less than that of Na.True or False?

    a) True

    b) False

7) Match the following :

    Element                         Flame colour 

    A) Li                                   M) Blue

    B) Na                                  N) Crimson red

    C) K                                    Q) Yellow

    D) Cs                                   P) Violet

    a) A-M,B-P,C-O,D-N

    b) A-N,B-O,C-M,D-P

    c) A-N,B-O,C-P,D-M

    d) A-O,B-N,C-P,D-M

8) Which among the following is the alkali metal that directly reacts with N in air to form the corresponding nitride?

    a) Rb

    b) K

    c) Li

    d) Na

9) Which superoxide among the following is the most stable one?

    a) CsO₂

    b) RbO₂

    c) KO₂

    d) All are equally stable

10) Alkali metals also react with H+ donors such as ROH,gaseous NH₃  and alkynes. True or False?

    a) False

    b) True

11) All alkali metal hydrides have : 

    a) Low melting point

    b) High melting point

12) Which among the following is more covalent?

    a) LiF

    b) LiCl

    c) LiBr

    d) LiI

13) Which is the most powerful reductant among alkali metals?

    a) Rb

    b) Li

    c) K

    d) Na

14) The colour imparted by alkali metals to liq NH₃  is :

    a) Deep blue

    b) Light blue

    c) Dark green

    d) Light green

15) The superoxides formed by alkali metals are :

    a) Paramagnetic

    b) Diamagnetic

    c) Ferromagnetic

    d) Ferrimagnetic

ANSWERS

1) c        2) b        3) b        4) d        5) a        6) a

7) c        8) c        9) a        10) b      11) b      12) d

13) b      14) a      15) a