JEE Advanced 2020 Concept Recapitulation Test 4 Paper 2

In acid rain in Delhi it was found that 1 litre rain water consist of 2.463 litre equimolar mixture of SO3 and NO2 gas dissolved at a partial pressure of 0.1atm. Find out the pH of the solution if HNO2 produced is 60% dissociated under given condition at 27∘C.(R=0.0821 litre atm/mole K) (log‌1.8=0.25)