The piston-cylinder below is depicted before and after a gaseous reaction that is carried out in it at constant pressure: the temperature is 150k before and 300 k after the reaction. (assume the cylinder is insulated.) which of the following balanced equations describes the reaction? group of answer choices a(g) + b2(g) latex: \longrightarrow ⟶ ab2 (g) a2(g) + b2(g) latex: \longrightarrow ⟶ 2ab(g) 2ab(g) + b2(g) latex: \longrightarrow ⟶ 2ab2(g) 2ab2(g) latex: \longrightarrow ⟶ a2(g) + 2b2(g)