Account for the following:
(i) State the relation between hydrogen ion concentration of an aqueous solution and its pH.
(ii) An aqueous solution has a pH value of 7.0 Is this solution acidic, basic or neutral.
(iii) Which has a higher pH value, 1M HCl or 1M NaOH solutions?
(iv) Tooth enamel is one of the hardest substances in our body. How does it undergo damange due to eating chocolates and sweets? What should we do to prevent it?

Explanation

(i) IF `H^+` ion concentration is more,pH will be less and vice versa or pH of a solution is inversely proportional to `H^+` ion concentration or pH=- log `(H^+)`
(ii) This solution is neutral.
(ii) 1M NaOH solution.
(iv) When the PH in the mouth is below 5.5 bacteria present in the mouth produce acids by degradation of sugar and corrode the tooth enamel. It can be prevented by using tooth pastes which are generally basic in nature.