Summary Chemistry: Acids and Alkalis

ACIDS AND ALKALIS

ACIDS:
-produce hydrogen ions (H+) when placed in aqueous solutions (water)
-acids have a pH below 7
-proton donors



ALKALIS:
-produce hydroxide ions (OH-) when placed in aqueous solutions.
- pH above 7
They accept a hydrogen ion which means their proton acceptors.



pH SCALE:
-measurement of how acidic or alkaline a solution is.
-scale goes from 0-14
-0 is very acidic- 14- very alkaline
-to measure pH we use universal indicator

-can also use a pH probe to measure pH- gives a numerical value from 0-14- more
accurately than using an indicator because it's less subjective.




NEUTRALISATION REACTIONS:
-acids react with alkalis to form salt and water- this is known as a neutralisation reaction

Acid + Base → Salt + Water
Eg: Hydrochloric Acid + Sodium Hydroxide → sodium chloride + water

The H+ ions in the acid and the OH- ions in the alkali react to form water

H+ + OH- → H2O -water will have a pH of 7- if you use a universal indicator, the solution will
turn green.