`MnO_2` on ignition converts into `Mn_3 O_4`. A sample of pyrolusite having `75% MnO_2, 20%` inert impurities and rest water is ignited in air to constant mass. What is the percentage of `Mn` in the ignited sample ?

Igniting MnO_(2) in air converts it quantitatively to Mn_(3)O_(4) . A sample of pyrolusite is of the following composition: MnO_(2) = 80% , SiO_(2) and other inert constituents = 15%, and rest bearing H_(2) O . The sample is ignited to constant weight. What is the percent of Mn in the ingnited sample?

A sample of impure cuprous oxide contains 66.67% copper, by ,mass. What is the percentage of pure Cu_2 O in the sample? (Cu=63.5)

100 g sample of clay (containing 19% H_(2)O , 40% silica, and inert inpurities as rest) is partically dried so as to contains 10% H_(2) O . Which of the following is//are correct statements (s) ?

A 120gm CaCO_(3) sample having inert impurities on heating produced 56gm of residue. Find % punity of sample .

A sample of iron ore, weighing 0.700 g, is dissolved in nitric acid. The solution is then, diluted with water, following with sufficient concentrated aqueous ammonia, to quantitative precipitation the iron as Fe(OH)_(3) . The precipitate is filtered, ignited and weighed as Fe_(2)O_(3) . If the mass of the ignited and dried preciipitate is 0.541 g, what is the mass percent of iron in the original iron ore sample (Fe=56)

If a sample of pure SO_(4) gas is heated to 600^(@) C, it dissociates into SO_(2) and O_(2) gases upto 50% .What is the average molar mass of the final sample.

A 200 gm sample of CaCO_(3) having 40 % purity is heated. Find moles of CO_(2) obtained.

25 gm of an oleum sample contains 15 gm H_(2)SO_(4) . What is % labellling of this oleum sample-

15 gm Ba(MnO_4)_2 sample containing inert impurity is completely reacting with 100 ml of 11.2 V' H_2O_2 , then what will be the % purity of Ba(MnO_4)_2 in the sample ? (Atomic mass Ba=137, Mn=55)

A 0.5 g sample containing MnO_(2) is treated with HCl liberating Cl_(2) is passed into a solution of KI and 30.0 " mL of " 0.1 M Na_(2)S_(2)O_(3) are required to titrate the liberated iodine. Calculate the percentage of MnO_(2) is the sample.