In which of the following compounds chlorine has highest oxidation state?

Given that $$\mathrm{C}_{(\mathrm{g})}+4 \mathrm{H}_{(\mathrm{g})} \longrightarrow \mathrm{CH}_{4(\mathrm{g})} \Delta \mathrm{H}^{\circ}=-1665 \mathrm{~kJ}$$

What is bond energy per mole of $\mathrm{C}-\mathrm{H}$ bond?

What type of information is collected using FTIR fourier transform infrared spectroscopy?

Which from following lanthanoids exhibits no effective magnetic moment in +3 state?