The decreasing order of bond angles in BF₃, NH₃, PF₃ and I₃^- is :

The IUPAC name of the following compound is :

An ideal gas undergoes a cyclic process as shown in Figure.


$$\Delta $$U_BC = $$-$$5 kJ mol^-1, q_AB = $$2$$ kJ mol^-1, W_AB = $$-$$5 kJ mol^-1, W_CA = 3 kJ mol^-1. Heat absorbed by the system during process $$CA$$ is :

Which of the following arrangements shows the schematic alignment of magnetic moments of antiferromagnetic substance ?