A sample of drinking water was found to be severly containated with chloroform, `CHCl_(3)` level of contamination was 15 ppm (by mass) Express this in per cent by mass.

A sample of drinking water was found to be severely contaminated with chloroform (CHC13) supposed to be a carcinogen. The level of contamination was 15 ppm (by mass): determine the molality of chloroform in the water sample.

A sample of 16 g charcoal was brought into contact with CH_(4) gas contained in a vessel of 1 litre at 27^(@) C . The pressure of gas was found to fall from 760 to 608 torr. The density of chacoal sample is 1.6 g//m^(3) . What is the volume of the CH_(4) gas adsorbed per gram of the adsorbent at 608 torr and 27^(@)C ? 125 L//g , 16.25 mL//g , 26 mL//g , none of these .

A certain public water supply contains 0.10ppb (part per billion) of chloroform (CHCI_3) . How many molecules of CHCI_3 would be obtained in 0.478 mL drop of this water ?(assumed d=1g/mL )

A reaction system in equilibrium according to reaction 2SO_(2)(g)+O_(2)(g)hArr2SO_(3)(g) in one litre vessel at a given temperature was found to be 0.12 mole each of SO_(2) and SO_(3) and 5 mole of O_(2) In another vessell of one litre contains 32 g of SO_(2) at the same temperature. What mass of O_(2) must be added to this vessel in order that at equilibrium 20% of SO_(2) is oxidized to SO_(3) ?

How much per cent of water and proteins present in total cellular mass?

A 1.025 g sample containing a weak acid HX (mol. Mass=82) is dissolved in 60 mL. water and titrated with 0.25 M NaOH. When half of the acid was neutralised the pH was found to be 5.0 and at the equivalence point the pH is 9.0. Calculate mass precentage of HX in sample :

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 ?

A 1.0g sample of a pure organic compound cotaining chlorine is fused with Na_(2)O_(2) to convert chlorine to NaCl. The sample is then dissolved in water, and the chloride precipitated with AgNO_(3) , giving 1.96 g of AgCl. If the molecular mass of organic compound is 147, how many chlorine does each molecule contain ?

Find mole fraction of ethanol and water in a sample of rectified spirit which contain 95 % ethanol by mass.

Calculate mole fraction of ethanol and water in a sample of rectified spirit which contains 92% ethanol by mass.