F5 Chem

first, calculate no. of mole of Na+ in each sol.
in sulphate sol., 1 mole of Na2SO4 gives 2 moles of Na+.
no. of mole = (volume) x (concentration) x (no. of mole of Na+ per mole of compound)
= (100/1000) x 2 x 2 = 0.4 mole

in nitrate sol., 1 mole of NaNO3 gives 1 mole of Na+
no. of mole = (50/1000) x 1 x 1 = 0.05 mole

total no. of mole after mixing = 0.45 mole
total volume of mixture = 100 + 50 = 150 cm^3
concentration = 0.45 / (150/1000) = 3.0M