Which one of the following electrolytes has the same value of van't Hoff factor (i) as that of Al₂(SO₄)₃ (if all are 100% ionised)?

The reaction of C₆H₅CH $$=$$ CHCH₃ with HBr produces

The activation energy of a reaction can be determined from the slope of which of the following graphs?

When initial concentration of a reactant is doubled in a reaction, its half-life period is not affected. The order of the reaction is