1-Salt and water is produced through the neutralization reaction of acid and base.
3-A strong acid is that dissociated all its molecules to ions when dissolved in water. But weak acid is that
dissociated a few of its molecules to ions when dissolved in water.
4-Is more acidic by one-hundred. That can be solved by observing the difference between PH 2 and PH 4 points and then to think that each point equal 10 folds,
Thus (10*10 = 100).
5-The hydrogen ion concentration increases when HCL is added to the water, and the pH decreases less tha 7 because the increasing of hydrogen ions.
6-No, the fish will not be fine in a lake that have a low Ph because the fish need water have a Ph number nearly to 7 , so it will die in a low pH lake.
7-I think the Ph number of soap will be 9 and not 4 , because the soap is made of very strong bases that have PH greater than 7.