6.488 g of lead combines directly with 1.002g of oxygen to form lead peroxide. Lead peroxide also can be prepared by heating lead nitrate. It was found that the percentage of oxygen present in lead peroxide prepared by the second experiment is 13.38. Use this data to illustrate the law of definite proportions.

The combination of elements of form compounds is governed by the laws of chemical combination. Hydrogen combines with oxygen to form compounds, namely water and hydroge peroxide. 28 g of nitrogen is mixed with 12 g of hydrogen to form ammonia as per the reaction, N_2 + 3H_2 rarr 2NH_3 . Which is the 'limiting reagent' in this reaction? [Atomic masses: N = 14, H = 1]

H2.SO4 used in lead storage.cell is '38 %' by mass and has a density of '1.30 g cm^-3 .' Calculate its molarity?

A 4.0 molar aqueous solution of NaCl is prepared and 500mL of this solution is electrolysed. This leads to the evolution of chlorine gas at one of the electrodes (Atomic mass: Na= 23: Hg=200, 1 faraday= 96500 coulomb) If the cathode is a Hg electrode, the maximum weight (in g) of Na-Hg amalgam formed from this solution is