AP EAMCET202119 Aug 2021Evening ShiftChemistryHydrogenActual
Assertion ( A ) : The colour of old lead paintings can be restored by washing them with a dilute solution of H 2 O 2 . Reason ( R ) : Hydrogen peroxide reduces PbS to Pb
Options
- ABoth A and R are true and R is a correct explanation for A
- BBoth A and R are true but R is not a correct explanation for A
- CA is true, R is false
- DA is false, R is true
Correct answer
C. A is true, R is false
Step-by-step solution
The colour of old lead paintings can be restored by washing them with a dilute solution of H 2 O 2 . The reaction is given below i.e. PbO Litharge → H 2 S PbS Black → H 2 O 2 PbSO 4 White Here, hydrogen peroxide acts as oxidising agent because oxidation state of sulphur changes from - 2 to + 6 so PbS is oxidised to PbSO 4 . So, Assertion is true while reason is false.