Which among following compounds is a secondary amine?

What is vapour pressure of a solution containing $$1 \mathrm{~mol}$$ of a non-volatile solute in $$36 \mathrm{~g}$$ of water? $$(\mathrm{P}_1^0=400 \mathrm{~mm} \mathrm{Hg}$$)

$$\mathrm{pH}$$ of soft drink is 3.6. Calculate the concentration of hydrogen ions in it.

Which of the following solutions behaves nearly as an ideal solution?