The one that is extensively used as a piezoelectric material is :

Consider the reversible isothermal expansion of an ideal gas in a closed system at two different temperatures T₁ and T₂ (T₁ < T₂). The correct graphical depiction of the dependence of work done (w) on the final volume (V) is :

A solution of sodium sulphate contains 92 g of Na⁺ ions per kilogram of water. The molality of Na⁺ ions in that solution in mol kg^$$-$$1 is :

The following results were obtained during kinetic studies of the reaction ;

2A + B $$ \to $$ Products

Experiment	[A] (in mol L$$-$$1)	[b] (in mol L$$-$$1)	Initial Rate of reaction (In mol L$$-$$1 min$$-$$1)
I	0.10	0.20	6.93 G 10$$-$$3
II	0.10	0.25	6.93 G 10$$-$$3
III	0.20	0.30	1.386 G 10$$-$$2

The time (in minutes) required to consume half of A is :