Which of the following dopant is NOT used in Ge to obtain n-type semiconductor?

2 g nonelectrolyte solute when dissolved in 50 g water increases its boiling point by 0.13 K.
Calculate the molar mass of solute if molal elevation constant of water is 0.52 K kg mol$^{-1}$

Which of the following aqueous solutions will show maximum vapour pressure at 300K?

Identify a pair of gases from following that does not obey Henry's law.