- AEinstein
- BLouis Pasteur
- CAristotle
- DLeuweenhock
Explanation:
A basic chemical hypothesis first emerged in Classical Greece with the theory of four elements as propounded definitively by Aristotle stating that the fire, air, earth and water were the fundamental elements.Everything is formed from a combination of two or more of these elements.
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${H_2}O + {H_2}PO^-_4 \rightleftharpoons {H_3}{O^ + } + HPO_4^{ - 2}$
Select out the group of acidic species lying on the right side of the equilibrium
Assertion $A$ :Phenolphthalein is a $pH$ dependent indicator, remains colourless in acidic solution and gives pink colour in basic medium
Reason $R$ : Phenolphthalein is a weak acid. It doesn't dissociate in basic medium.
In the light of the above statements, choose the most appropriate answer from the options given below.