Alkali metal

Question 1

atomic radius down the group (group 1)

Answer 1

increases

Question 2

density down the group (group 1)

Answer 2

increases

exception - Na > K

Question 3

flame color of Li (group 1)

Answer 3

chrimson red

Question 4

flame color of Na (group 1)

Answer 4

yellow

Question 5

flame color of K (group 1)

Answer 5

violet

Question 6

flame color of Rb (group 1)

Answer 6

red-violet

Question 7

flame color of Cs (group 1)

Answer 7

blue

Question 8

electronegativity down the group (group 1)

Answer 8

decreases

Question 9

electron affinity down the group (group 1)

Answer 9

decreases

Question 10

metallic bond strength down the group (group 1)

Answer 10

decreases

Question 11

in s block, minimum S.R.P. is of (group 1)

Answer 11

lithium

Question 12

in s block, maximum S.R.P. is of (group 1)

Answer 12

sodium

Question 13

hydration energy is proportional to (group 1)

Answer 13

charged density

Question 14

which of the elements can be used as electrodes in photoelectric cell (group 1)

Answer 14

Cs and K

Question 15

why are alkali metals very reactive (group 1)

Answer 15

because of low I.E. , they tend to form ionic bond faster by fajan’s rule

Question 16

general element formed on reaction in air (group 1)

Answer 16

N2: Lithium nitride only
O2: OXIDE, PEROXIDE AND SUPEROXIDE

Question 17

forms normal oxide on reaction with O2 (group 1)

Answer 17

Li

Question 18

forms peroxide on reaction with O2 (group 1)

Answer 18

Na

Question 19

forms superoxide on reaction with O2 (group 1)

Answer 19

K, Rb, Cs

Question 20

which have highest hydration energy (group 1)

Answer 20

Li

Question 21

Li shows diagonal relationship with (group 1)

Answer 21

Mg

Question 22

general compound on reaction with H2 (group 1)

Answer 22

MH

ionic salt like hydride

Question 23

general compound on reaction with halogen (group 1)

Answer 23

MX

it forms ionic compound but lithium halides are somewhat covalent due to fajan’s rule

Question 24

reactivity with H2O down the group (group 1)

Answer 24

decreases

Question 25

reducing nature down the group (group 1)

Answer 25

increases

exception - lithium has maximum

Question 26

reacts least rapidly with H2O (group 1)

Answer 26

Li

Due to High MP

Question 27

MP and BP down the Group (group 1)

Answer 27

Decreases

Question 28

liq NH3+ alkali metal (group 1)

Answer 28

Blue colour solution
paramagnetic
both of this is due to ammoniated electrons

Question 29

why do the solution become bronze in colour on standing (group 1)

Answer 29

blue colour disappears as the electrons forms amide

solution losses its e- thus it also looses the paramagnetic property of the solution and become diamagnetic

Question 30

Al + Li is used in (group 1)

Answer 30

Aircraft

Question 31

Li + Mg is used for (group 1)

Answer 31

Armour

Question 32

white metals are (group 1)

Answer 32

alloys of Li

Question 33

White metals are used in (group 1)

Answer 33

ball bearings for motor engines

Question 34

Na + Pb alloy is used in

Answer 34

anti knock additives in petrol

Question 35

what act as an liquid coolent in fast breeding nuclear reactor (group 1)

Answer 35

Liq Na

Question 36

absorbs CO2 (group 1)

Answer 36

KOH

Question 37

used in soaps (group 1)

Answer 37

KOH, NaOH

potassium soaps are softer for skin than the sodium soaps.

Question 38

Lithium shows anomalous behavior because (Group 1)

Answer 38

1. small size

2. high polarizing power

Question 39

The bicarbonate salts (Group 1)

Answer 39

solid except LiHCO3

Question 40

M2CO3 on heating (Group 1)

Answer 40

Li : Li2O +CO2

Na, K , Rb , Cs : no reaction

Question 41

LiNO3 heat (Group 1)

Answer 41

Li2O + NO2

Question 42

NaNO3 500 C (Group 1)

Answer 42

NaNO2 +O2

Question 43

NaNO3 800 C (Group 1)

Answer 43

NaNO2 + N2 +O2