CHAPTER 2.

ACIDS,BASES AND SALTS.

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INDICATORS ARE THE CHEMICAL SUBSTANCES WHICH

CAN TELL US THAT ANY SUBSTANCES ARE ACID, BASE OR

SALT( NEUTRAL).

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INDICATORS CAN CHANGE IT COLOUR AND ITS SMELL IN

ACID AMD BASE.

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TYPES OF INDICATORS:

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NATURAL : LITMUS (FROM LICHENS) AND TURMERIC.

WHEN RED LITMUS TURNS INTO BLUE THEN SOLUTION IS

BASIC.

WHEN BLUE LITMUS TURNS INTO RED THEN SOLUTION IS

ACIDIC.

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SYNTHETIC: PHENOLPHTHALEIN, METHYL ORANGE

PHENOLPHTHALEIN IS COLOURLESS WHEN IT TURNS INTO

PINK THE SOLUTION IS BASIC.

IN ACID IT REMAIN COLOURLESS.

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OLFACTORY: ONION, CLOVE OIL AMD VANILLA.

ONION IN BASIC BASIC SOLUTION: SMELL TO ODOURLESS.

ONION IN ACIDIC SOLUTION: SMELL TO SMELL.