Question

18. From the list of the following substances, choose the
substance that most appropriately fits the description
given in the following:
Blue vitriol, table salt, sulphuric acid, washing soda,
caustic soda
(a) A hygroscopic substance
(b) A deliquescent salt
(c) A hydrated salt
(d) A substance having no water molecule of
crystallisation
(e) Efflorescent substance
19. Explain temporary and permanent hardness of water.
20. How does boiling remove temporary hardness of
water?
21. Is hard water suitable for being used in boilers? If not,
why?
22. Give five examples of hydrated salts with their chemical
formulae.
23. Explain hygroscopy and deliquescence with examples.
24. What is the difference between a drying agent and a
dehydrating agent?
25. If calcium carbonate is put in distilled water, will it
cause hardness. If not, why?​

Answer 1

Answer:

a) sulphuric acid

b) blue vitriol

c) washing soda

d) table salt

e) caustic soda