(a) Sometimes the pH of our mouth gets lower than 5·5. Why ? (b) A basic salt 'X' is obtained by heating…
(a) Sometimes the pH of our mouth gets lower than 5·5. Why ?
(b) A basic salt 'X' is obtained by heating baking soda followed by crystallisation. Identify 'X' and state its two industrial uses.
(c) Why do copper sulphate crystals turn white on heating ?
Solution
(a) Bacteria present in the mouth produce acids by degradation of sugar and food particles remaining in the mouth after eating.
(b) X : Na2CO3 . 10H2O / Washing soda / Sodium carbonate decahydrate
Uses:
*Glass, soap and paper industries
*Manufacture of borax
*Cleaning agent
*Removing permanent hardness of water (any two)
(c) The water of crystallisation is removed. /
CuSO4 . 5H2O $\xrightarrow{\text{heat}}$ CuSO4 + 5H2O (white) (gas evolved)