Answer: 19.4 grams of chlorine
Step-by-step explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

According to avogadro's law, 1 mole of every substance weighs equal to the molecular mass and contains avogadro's number
of particles.
4 moles of
decompose to give 6 moles of

of
decompose to give
of

Thus 25 g of
decompose to give
of

Thus 19.4 grams of chlorine will be produced.