State reason for the following statements:
(1) Tap water conducts electricity whereas distilled water does not.
(ii) Dry hydrogen chloride gas does not turn blue litmus red whereas dilute hyd
acid does.
(iii) During summer season, a milk man usually adds a very small amount of ba
soda to fresh milk.
(iv) For a dilution of acid, acid is added into water and not water into acid.
(v) Ammonia is a base but does not contain hydroxyl group.
Answers
Explanation:
1)Electricity is conducted through liquids by ions. Tap water conducts electricity due to presence of ions of dissolved salts and minerals in it. But distilled water which is a covalent compound has no ions to conduct electricity through it.
2)Dry hydrogen chloride gas doesn't give hydrogen ions and so it doesn't act as an acid and doesn't turn blue litmus paper red. Whereas hydrogen chloride acid gives H+ ions and turns blue litmus paper red
3) Baking soda acts as a bit preservative. It makes milk a bit alkaline so as to reduce the pace of bacteria acting on it, as they add acids i.e lactic acid and turns it sour. This keeps the milk from becoming sour for long time.
4) Dilution of concentrated acid is exothermic process. If water is added to concentrated acid, the heat generated may cause the mixture to splash out and cause burns. When acid is added to water slowly with constant stirring it will splash out.
5)Ammonia (NH3) is a weak base, which does not have hydroxyl group in its formula but it gives OH- ions when it reacts with water.