Notes chemistry - 10th class-chapter- Acid Base Salt

Acid , Bases,salt

Notes 10th class

Indicators: indicators are substances which shows different colour in acid and bases medium. Example are phenolphthalein, methyl orange and litmus solution

Olfactory indicators: These indicators change smell in acidic and basic medium

Example: onion, vanilla, clove.

Acid and bases react with metals to produce hydrogen gas which burn with pop sound

Chemical equations:

Mg(s)+2HCL. >>>>>>>>Mgcl2+ H2

Acid react with metal carbonate to produce carbon dioxide gas

Carbon dioxide turn lime water milky due to formation of calcium carbonate. But excess of CO2 makes milkiness disappear due to formation of soluble calcium bicarbonate

Acid react with base to form salt and water . This is called nutralisation reaction.

Metallic oxides are basic in nature whereas non metallic oxides are acidic

PH scale: it is a scale ranging from 0 to 14 for measuring hydrogen ions concentration

PH = 7 indicate neutral nature

PH>7 are basic

PH < 7 are acidic

Our body works in narrow range PH 7 to 7.8

The rain becomes acid rain when pH become < 5.6

When pH of our mouth become less than 5.5 the tooth enamel starts corroding