S-Block Elements

Question 1

Alkali Metals: IE down the group

Answer 1

decreases

Question 2

Alkali Metals: hardness

Answer 2

decreases down the group

Question 3

Alkali Metals mpt and bpt

Answer 3

Decreases down the group

Question 4

Flame colour with HCl: Li,Na,K,Rb,Cs

Answer 4

Crimson, Yellow, Lilac, Red violet, Blue

Question 5

density of alkali metals when compared with water

Answer 5

is lesser

Question 6

photoelectric effect is shown by alkali metals except

Answer 6

Lithium

Question 7

Cs is less solvated than Li bcoz

Answer 7

ionic mobility of alkali metals increases along the group
because charge density decreases down the group.

Question 8

Reducing power order of alkalimetals. State reason too

Answer 8

Na<K<Cs<Rb<Li
due to standard reduction potential

Question 9

color of soln in NH3(l)

Answer 9

blue, paramagnetic in low conc
bronze,diamagnetic in high conc

Question 10

colour of Li oxide and Na oxide

Answer 10

White crystals

Question 11

colour of K2O

Answer 11

Pale yellow

Question 12

colour of Rb2O

Answer 12

yellow

Question 13

colour of Cs2O

Answer 13

orange

Question 14

which method is better for preparing Na20,k2o,rb2o,Cs2o?
(i) Limited air supply
(ii) Thermal decomposition of peroxides, superoxides

Answer 14

ii

Question 15

Order of basic character of oxides

Answer 15

Increases down the group

Question 16

_____are better solvated.
i) ions of smaller size elements
ii) ions of greater size elements of the same group

Answer 16

i)

Question 17

metal oxide+water

Answer 17

metal hydroxide

Question 18

metal peroxide+water

Answer 18

metal hydroxide+ h2O2

Question 19

metal superoxide+water

Answer 19

metal hydroxide+ H2O2 + O2