Q81.The orbital angular momentum for an electron revolving in an orbit is given by √l(l + 1) ⋅ 2πh . This momentum for an s-electron will be given by (1) zero (2) h 2π (3) √2 ⋅ 2πh (4) + 21 ⋅ 2πh JEE Main 2003 JEE Main Previous Year Paper

Q90.Which one of the following aqueous solutions will exhibit highest boiling point? (1) 0.01MNa2SO4 (2) 0.015M glucose (3) 0.015M urea (4) 0.01MKNO3

Q79.Two solutions of a substance (non electrolyte) are mixed in the following manner. 480 ml of 1.5 M first solution + 520 mL of 1.2 M second solution. What is the molarity of the final mixture? (1) 1.20 M (2) 1.50 M (3) 1.344 M (4) 2.70 M

Q92.Benzene and toluene form nearly ideal solutions. At 20∘C, the vapour pressure of benzene is 75 torr and that of toluene is 22 torr. The partial vapour pressure of benzene at 20∘C for a solution containing 78 g of benzene and 46 g of toluene in torr is (1) 50 (2) 25 (3) 37.5 (4) 53.5