The number of optically active compounds from the following is _________.

Two moles of benzaldehyde and one mole of acetone under alkaline conditions using aqueous $$\mathrm{NaOH}$$ after heating gives $$x$$ as the major product. The number of $$\pi$$ bonds in the product $$x$$ is ______.

A solution is prepared by adding 1 mole ethyl alcohol in 9 mole water. The mass percent of solute in the solution is ________ (Integer answer) (Given : Molar mass in $$\mathrm{g} \mathrm{~mol}^{-1}$$ Ethyl alcohol : 46 water : 18)

Molality of an aqueous solution of urea is $$4.44 \mathrm{~m}$$. Mole fraction of urea in solution is $$x \times 10^{-3}$$, Value of $$x$$ is ________. (Integer answer)