Group 1 compound dissolves to have pH higher than 7. Make
indicators change colour (litmus turns BLUE in alkali, red in acid). Alkali
neutralises acid to make salt. NEUTRALISATION. Soluble metal
carbonates and soluble metal hydroxides.
Anode
POSITIVE electrode in
Electrolysis.- with brine,
CHLORINE forms
Bases
INSOLUBLE metal hydroxides and metal carbonates.
React with acids in similar way that alkalis do, but DON'T
affect indicators.
Chlorine
Benefits- Killed water-borne micro-organisms that
caused diseases like Cholera and typhoid.
CORRELATION between start of chlorination in USA
an fall in number of deaths.
Risks-THM's can cause cancer.
Reacts with organic matter. It is a
toxic fas- causes health problems
such as asthama.