Question

12. When calcium carbonate is heated, it decomposes to give_______and______
13. Fatty foods become rancid due to the process of
(a) oxidation (b) corrosion
(c) reduction
(d) hydrogenation
14. We store silver chloride in a dark coloured bottle because it is
(a) a white solid
(b) undergoes redox reaction
(c) to avoid action by sunlight
(d) none of the above
15. When carbon dioxide is passed through lime water,
(a) calcium hydroxide is formed
(b) white precipitate of CaO is formed
(c) lime water turns milky
(d) colour of lime water disappears.
16. Rancidity can be prevented by
(a) adding antioxidants
(b) storing food away from light
(c) keeping food in refrigerator
(d) all of these
17. The reaction in which two compound exchange their ions to form two new compound
called
(a) displacement reaction
(b) combination reaction
(c) double displacement reaction (d) redox reaction
18. On immersing an iron nail in CuSO4 solution for few minutes, you will observe
(a) no reaction takes place
(b) the colour of solution fades away
(c) surface of iron nails acquire a black coating (d) the colour of solution changes to
9. White silver chloride in sunlight turns to
a)Greyb)
Yellow
c)Remain white
Black and white photography uses
d )Red
a)Decomposition of silver chloride b)Decomposition of silver bromide
Both​

Answer 1

Answer:

12.calcium ,carbon dioxide

13.a

14.c

15.c

16d

17c

18d

19a

20Both

Answer 2

Answer:

hope these are the answers...