A sample of drinking water was found to be severly contaminated with chlorofoem `(CHCl_3)`, supposed to be a carcinogen. The level of contmination was 15ppm (by mass):
determine the molality of the chloroform in the water sample.

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.

6.2g of a sample containing Na_2CO_3, NaHCO_3 and non-volatile inert impurity on gentle heating loses 5% of its mass due to reaction 2NaHCO_3 rarr Na_2 CO_3 + H_2 O + CO_2 . Residue is dissolved in water and formed 100mL solution and its 10mL portion requires 7.5 mL of 0.2M aqueous solution of BaCI_2 for complete precipitation of carbonates. Determine mass (in gram) of Na_2 CO_3 in the original sample.

If hardness of water sample is 200 parts per million , Calculate the mass ratio of CaCO3 to water is:

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 :

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 ?

One litre of a sample of hard water contain 4.44mg CaCl_(2) and 1.9mg "of" MgCl_(2) . What is the total hardness in terms of ppm of CaCO_(3)?

Calculate the normal freezing point of a sample of sea water containing 3.8% NaCl and 0.12% MgCl_2 by mass. (K_f for water=1.86Km^-1)

Oleum is considered as a solution of SO_(3) in H_(2)SO_(4) , which is obtained by passing SO_(3) in solution of H_(2)SO_(4) When 100 g sample of oleum is diluted with desired mass of H_(2)O then the total mass of H_(2)SO_(4) obtained after dilution is known is known as % labelling in oleum. For example, a oleum bottle labelled as ' 019% H_(2)SO_(4) ' means the 109 g total mass of pure H_(2)SO_(4) will be formed when 100 g of oleum is diluted by 9 g of H_(2)O which combines with all the free SO_(3) present in oleum to form H_(2)SO_(4) as SO_(3)+H_(2)O to H_(2)SO_(4) If excess water is added into a bottle sample labelled as "112% H_(2)SO_(4) " and is reacted with 5.3 g NaCO_(3) then find the volume of CO_(2) evolved at 1 atm pressure and 300 K temperature after the completion of the reaction :

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 1.0 g sample of co (NH_(2)CH_(2)CH_(2)NH_(2))_(3)Cl_(3) is dissolved in 25.0 g if water and the freezing point of the solution is -0.87^(@)C . How many ions are produced per mole of compound? The K_(f) of water is 1.86^(@)C//"molal"