`10L` of hard water required `5.6g` of lime for removing haardness. Hence temporary hardness in ppm of `CaCO_3` is :

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)?

RH_2 (ion exchange resin) can replace Ca^(2+) ions in hard water as RH_2+Ca^(2+)rarr RCa+2H^+ . If 1 L of hard water after passing through RH_2 has pH=3 then hardness in parts per million of Ca^(2+) is :

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 :

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.

A company manufactures two types of novelty souvenirs made of plywood. Souvenirs of type A require 5 minutes each for cutting and 10 minutes each for assembling. Souvenirs of type B require 8 minutes each for cutting and 8 minutes each for assembling. There are 3 hours 20 minutes available for cutting and 4 hours for assembling. The profit is Rs 5 each for type A and Rs 6 each for type B souvenirs. How many souvenirs of each type should the company manufacture in order to maximise the profit?

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

Salt ‘A’ commonly used in bakery products on heating gets converted into another salt ‘B’ which itself is used for removal of hardness of water and a gas ‘C’ is evolved. The gas ‘C’ when passed through lime water, turns it milky. Identify A, B and C.

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: