Question

Give reason
1) toothpaste are generally basic
2) ph of rain water is 5.6
3) on diluting acid, acid should be added to water and not water to acid
4) co2 turns limewater milky
5) acids and alkali are good conductors of electricity
6) co2 reacts with naoh, not with hcl

Answer 1

1. because the ph of teeth is low due to acids released by the pathogens and to neutralise the effect of acid.

2. this happens when oxides of sulphur and other oxides react with water to form acids.

3. when we put acid to water there is enormous amount of heat is produced which is absorbed by water but when we put water in acid the heat produced is not absorbed and causes blast.

4. co2 reacts with lime water to for caco3 which is white in color and in insoluble in water.

5.acids when mixed in water makes hydrogen ions which conduct electricity similarly alkali form hydroxide ions which also conduct electricity.

6. as oxides of non metals are acidic in nature therefore co2 only reacts with naoh not with hcl