rxn - metal + o2

Question 1

metal + o2 -> ?

Answer 1

metal oxides

Question 2

metal oxides are ——– in nature

Answer 2

basic, (red litmus -> blue)

Question 3

The vigor of rxn depends on?

Answer 3

reactivity of the metal

Question 4

EX 1: na + o2 -> ?, temp?

Answer 4

4na + o2 -> 2na2o, happens at room temp

Question 5

EX 2: 4K + o2 -> ?, temp? details?

Answer 5

4K + o2 -> 2k2o, catch fire if kept in open and bcs of tht they are stored under kerosene oil to prevent rxn with o2, moisture, co2

Question 6

except potassium wht else is stored under kerosene

Answer 6

lithium

Question 7

3 alkali metals?

Answer 7

na, k, li

Question 8

most metal oxides are ——– in h20?

Answer 8

insoluble but some are

Question 9

na2o, k2o + h2o -> ?

Answer 9

2Naoh, 2KOH -> basic in nature

Question 10

EX3: 2Mg +o2 -> temp? details?

Answer 10

2Mg +o2 -> 2Mgo(white powder), reacts on heating not at room temp, forms intense heat/light

Question 11

mg oxide in water?

Answer 11

dissolves partially to give hyrdroxide Mg(oh)2 -> basic

Question 12

EX4: 4al+ 3o2 ->? temp? type o oxide

Answer 12

2al2o3, on heating, amphoteric oxide

Question 13

what are amphoteric oxides?

Answer 13

metal oxides that show basic and acidic prps both ex - al, zn, oxides

Question 14

amphoteric oxide + acid/base ->

Answer 14

amphoteric oxide + acid/base -> salt + h20

Question 15

Fe case with o2

Answer 15

It does not burn even on strong heating, 3Fe + 2O2 -> Fe3O4 Iron (II,III) oxide, a piece of iron will not burn but iron fillings burn when sprinkled in burners flame

Question 16

cu case with o2

Answer 16

2cuO (black) (copper II oxide) burns on prolonged heating