`CS_2` is a colourless, highly inflammable liquid used in the manufacture of rayon and cellophane. A sample contains 0.0205 mol `CS_2`. Calculate the mass of `CS_2` in the sample.

Boric acid, H_3 BO_3 is a mild antiseptic and is often used as an eye wash. A sample contains 0.543 mol H_3 BO_3 . What is the mass of boric acid in the sample?.

Nitric acid, HNO_3 is a colourless, corrosive liquid used in the manufacture of Nitrogen fertilizers and explosives. In an experiment to develop new explosives for mining operations, a 28.5 g sample of HNO_3 was poured into a beaker. How many moles of HNO_3 are there in this sample of HNO_3 ?

The molality of a sulphuric acid solution is 0.2"mol"//"kg" Calculate the total weight of the solution :

H_2O_2 is a colourless liquid. A concentrated solution of it is used as a source of oxygen for Rocket propellant fuels. Dilute aqueous solutions are used as a bleach. Analysis of a solution shows that it contains 0.909 mol H_2 O_2 in 1.00 L of solution. What is the mass of H_2 O_2 in this volume of solution?

36% amount of a radioactive sample distegrates in t time. Calculate how much percentage fraction will decay in t//2 time.

A sample of water from a large swimming pool has a resistance of 9200 Omega at 25^(@)C when placed in a certain conductance cell. When filled with 0.02M KCI solution the cell has a resistance of 85 Omega at 25^(@)C. 500g of NaCI were dissolved in the pool, which was throughly stirred. A sample of this solution gave a resistance of 7600 Omega . calculate the volume of water in the pool. Given: Molar conductance of NaCI at that concentration is 126.5 Omega^(-1) cm^(2) mol^(-1) and molar conductivity of KCI at 0.02M is 138 Omega^(-1) cm^(2) mol^(-1) .

As shown in the figure two cylindrical vessels A and B are interconnected . Vessel A contains water up to 2m height and vessel B contains kerosene . Liquids are separated by movable, airtight disc C . If height of kerosene is to be maintained at 2m , calculate the mass to be placed on the piston kept in vessel B. Also calulate the force acting on disc C due to this mass. Area of piston =100cm^(2) , area of disc C=10cm^(2) , Density of water =10^(3)kgm^(-3) , specific density of kerosene =0.8 .