IIT-JEE Advance - Previous Year Papers Previous Year Questions

Naturally occurring boron consists of two isotopes whose atomic weighs are 10.01 and 11.01. The atomic weight of natural oron is 10.81. Calculate the percentage of each isotope in natural boron.

5 ml of a gas containing only carbon and hydrogen were mixed with an excess of oxygen (30 ml) and the mixture exploded by means of an electric spark. After the explosion, the volume of the mixed gases remaining was 25 ml. On adding a concentrated solution of potassium hydroxide, the volume further diminished to 15 ml of the residual gas being pure oxygen. All volumes have been reduced to N.T.P. Calculate the molecular formula of the hydrocarbon gas.

A mixture contains NaCl and unknown chloride MCl.

(i) 1g of this is dissolved in water. Excess of acidified AgNO₃ solution is added to it. 2.567 g of white ppt is formed.

(ii) 1 g of original mixture is heated to 300^oC. Some vapours come out which are absorbed in acidified AgNO₃ solution, 1.341 g of white precipitate was obtained.

Find the molecular weight of unknown chloride.

When a person walks on a rough surface, the frictional force exerted by the surface on the person is opposite to the direction of his motion.

The outer electronic configuration of the ground state chromium atom is 3d⁴ 4s²

Two balls of different masses are thrown vertically upwards with the same speed. They pass through the point of projection in their downward motion with the same speed. (Neglect air resistance)