Name the sodium compound which is used for softening hard water

NCERT solutions of related questions for Acids, Bases and Salts • You are given three test tubes. The three test tubes contain distilled water, acidic solution and the basic solution respectively. There is only red litmus paper available in order to identify what is there in each test tube. How will you find out what is in each of the test tubes? • Why should curd and sour substances not be kept in brass and copper vessels? • Which gas is usually liberated when an acid reacts with a metal? Illustrate with an example. How will you test for the presence of this gas? • Metal compound A reacts with dilute hydrochloric acid to produce effervescence. The gas evolved to extinguish a burning candle. Write a balanced chemical equation for the reaction if one of the compounds formed is calcium chloride. • Why do \(HCl , HNO_3 \) etc., show acidic characters in aqueous solutions while solutions of compounds like alcohol and glucose do not show acidic character? • Why does an aqueous solution of an acid conduct electricity? • Why does dry \( HCl \) gas not change the colour of the dry litmus paper? • While diluting an acid, why is it recommended that the acid should be added to water and not water to the acid? • How is the concentration of hydronium ions \( H_3 O^+ \) affected when a solution of an acid is diluted? • How is the concentration of hydroxide ions \(OH^– \) affected when excess base is dissolved in a solution of sodium hydroxide? • You have two solutions, A and B. The pH o...