When sulfur dioxide is bubbled through a solution containing bromothymol blue, the solution changes from blue to yellow because sulfur dioxide _______________________.
reacts with water to form sulfuric acid
this is the "acid rain" reaction
Not quite. The reaction is
SO2 + H2O ==> H2SO3 which is sulfurous acid. It is true, however, that the SO2 gets blown into the higher atmosphere where it may react with O2 to form SO3 and that reacts, as you show, to form sulfuric acid.
When sulfur dioxide is bubbled through a solution containing bromothymol blue, the solution changes from blue to yellow because sulfur dioxide reacts with water to form sulfurous acid (H2SO3).
To understand why the solution changes from blue to yellow when sulfur dioxide is bubbled through a solution containing bromothymol blue, we need to examine the chemical reaction involved.
Sulfur dioxide (SO2) is a gas that dissolves in water to form sulfurous acid (H2SO3). Bromothymol blue is a commonly used pH indicator that changes color depending on the acidity or alkalinity of a solution. It is blue in alkaline solutions and yellow in acidic solutions.
When sulfur dioxide is bubbled through the solution, it reacts with water to produce sulfurous acid, which increases the acidity of the solution. As a result, the pH decreases, turning the bromothymol blue indicator from blue to yellow.
In summary, when sulfur dioxide is bubbled through a solution containing bromothymol blue, the solution changes from blue to yellow because the sulfur dioxide reacts with water to form sulfurous acid, increasing the acidity of the solution and causing the color change of the pH indicator.