2L of 0.2M H2SO4 is reacted with 2L of 0.1M NaOH solution, the molarity of the resulting product Na2SO4 in the solution is _________ millimolar. (Nearest integer)
Metal $$\mathrm{M}$$ crystallizes into a fcc lattice with the edge length of $$4.0 \times 10^{-8} \mathrm{~cm}$$. The atomic mass of the metal is ____________ $$\mathrm{g} / \mathrm{mol}$$. (Nearest integer)
$$\left(\right.$$ Use : $$\mathrm{N}_{\mathrm{A}}=6.02 \times 10^{23} \mathrm{~mol}^{-1}$$, density of metal, $$\mathrm{M}=9.03 \mathrm{~g} \mathrm{~cm}^{-3}$$ )
If the wavelength for an electron emitted from $$\mathrm{H}$$-atom is $$3.3 \times 10^{-10} \mathrm{~m}$$, then energy absorbed by the electron in its ground state compared to minimum energy required for its escape from the atom, is _________ times. (Nearest integer)
$$\left[\right.$$ Given $$: \mathrm{h}=6.626 \times 10^{-34} \mathrm{~J} \mathrm{~s}$$ ]
Mass of electron $$=9.1 \times 10^{-31} \mathrm{~kg}$$
A gaseous mixture of two substances A and B, under a total pressure of $$0.8$$ atm is in equilibrium with an ideal liquid solution. The mole fraction of substance A is $$0.5$$ in the vapour phase and $$0.2$$ in the liquid phase. The vapour pressure of pure liquid $$\mathrm{A}$$ is __________ atm. (Nearest integer)