Acid rain
Environmental Chemistry · Chemistry
Study notes
Why does the Taj Mahal yellow despite no local industry? Step 1: Mathura refinery + vehicles emit SO₂/NOₓ upwind. Step 2: SO₂ → H₂SO₄ in atmosphere → acid rain (pH < 5.6). Step 3: CaCO₃ (marble) + H₂SO₄ → CaSO₄ (gypsum crust, yellowish). Step 4: Acid rain travels — pollution's long arm etches marble!