A balloon is filled with `CO_(2)`. How will it behave as a lens for sound waves? What happens if `CO_(2)` is replaced by hydrogen?

A ballon is filled with NO_(2) gas. How will it behave as a lens for sound entering it from air ? Will it be converging or diverging ? What if the gas is now replaced with H_(2) gas ?

Statement-1 : A balloon filled with CO_(2) gas acts as a coverging lens for a sound wave Statement-2 : Sound waves travel faster in air than in CO_(2)

A balloon is filled with hydrogen. For sound waves, this balloon behaves like

(True/False): A balloon is filled with hydrogen gas. For sound waves it acts as a convex lens.

What happens when excess of CO_2 is passed through lime water ?

What happens when phenol is warmed with CO_(2) in the presence of aqueous NaOH?

A plant is kept in 300ppm CO_(2) concentration, what will happen to it