CBSE Class 10 Science 2019 · Paper 31/1/1/C · Question 6

(a) Oxidant: ${\text{MnO}}_2$, which loses oxygen and is itself reduced to ${\text{MnCl}}_2$. Reductant: $\text{HCl}$, which loses hydrogen and is itself oxidised to ${\text{Cl}}_2$. (b) (i) Fats and oils in food are oxidised by the oxygen of the air and turn rancid, spoiling the smell and taste; antioxidants prevent this oxidation. (ii) In sunlight, white silver chloride decomposes into grey silver and chlorine gas: $2\text{AgCl}(s)\stackrel{\text{sunlight}}{\to }2\text{Ag}(s)+{\text{Cl}}_2(g)$.