Identify the correct decreasing order of thermal stability from following.

What is the number of moles of N atoms and number of moles of O atoms respectively present in one mole of uracil?

Which from following molecules exhibits lowest dipole moment?

Identify the number of moles of ethene obtained when n moles of $\mathrm{N}, \mathrm{N}, \mathrm{N}$-triethylpropylammonium iodide is treated with moist $\mathrm{Ag}_2 \mathrm{O}$ and then heated.