(a). IF both (A) and (R) are correct and (R) is the correct explanation of (A).
(b). If both (A) and (R) are correct but (R) is not the correct explanation of (A).
(c). If (A) is correct, but (R) is incorrect.
(d). If (A) is incorrect, but (R) is correct. ltbr. (e) if both (A) and (R) are incorrect.
Q. Assertion (A): In the titration of `Na_(2)CO_(3)` with HCl using methyl orange indicator the volume required at the equivalence point is twice that of the acid requried using phenolphthalein indicator.
Reason (R): 2 " mol of "HCl are requried for complete neutralisation of one mole of `Na_(2)CO_(3)`.

Answer

B

Explanation

" Eq of "`Na_(2)CO_(3)=" Eq of "HCl`
`(1)/(2) " mol of "Na_(2)CO_(3)=(1)/(1)" mol of "HCl`
`1 " mol of "Na_(2)CO_(3)=2 " mol of "HCl`
both (A) and (R) are correct but (R) is not correct explanation of (A).