Weight of copper oxide obtained by treating 2.16 g metallic copper with nitric acid and subsequent ignition was 2.70 g. In another experiment, 1.15 g of copper oxide on reduction yielded 0.92 g of copper. Show that these results illustrate the law of definite proportions.

A current of 4 amp was passed for 1.5 hours through a solution of copper sulphate when 3.2 g of copper was deposited. Calculate the current efficiency.

X-ray diffranction studies show that copper crystallises in an fcc unit cell with cell edge of 3.608x10^(-8) cm. In a separate experment, copper is determined to have a density of 8.92 g cm^-3 , calculate the atomic mass of copper.

What is the emprical formula of vanadium oxide , if 2.74g of the metal oxide contains 1.53g of metal ?

Silver oxide (Ag_2O) decomposes at temperature 300^@C yielding matellic silver and oxygen gas. A 1.60g sample of impure silver oxide yields 0.104g of oxygen gas. What is the per cent by mass of the silver oxide in the sample ?

A copper atom consists of copper nucleus surrounded by 29 electrons. The atomic weight of copper is 63.5mol e^(-1) . Let us now take two pieces of copper each weighing 10g. Let us trandfer one elcetron from one piece to another for every 100 atoms in that piece. What will be the Coulomb force between the two pieces after the trandfer of electrons, if they are 1cm apart? Avogadro number= 6xx10^(23) mol e^(-1) , charge on an electron =- 1.6xx10^(-19)C.

A metal oxide has the formula X_2O_3 . It can be reduced by hydrogen to give free metal and water. 0.1596g of metal oxide requires 6mg of hydrogen for complete reduction. The atomic mass of the metal (in amu) is :

A mixture of H_(2)SO_(4) and H_(2)C_(2)O_(4) (oxalic acid ) and some inert impurity weighing 3.185 g was dessolved in water and the solution made up to 1litre. 10 mL of this solution required 3 mL of 0.1 N NaOH for complete neutralization. In another experiment 100 mL of the same solution in hot condition required 4 mL of 0.02 M KMnO_(4) solution for complete reaction. The mass % of H_(2)SO_(4) in the mixture was: