5: (a) The soil in a field is highly acidic. List any two materials which can be added to this soil to reduce its acidity. Give the reason for your choice. [CBSE 2016](b) A gas produced in the laboratory is highly soluble in water. Its colourless solution turns pink when a few drops of phenolphthalein is added to it. What is the nature of this gas?Ans: (a) (i) Lime, (CaO) can be added to neutralize acidity.(ii) Chalk, (CaCO3) can also be added to neutralise acidity.It is because CaO and CaCO3 are basic in nature which neutralize acid present in soil.(b) The nature of gas is basic because it turns phenolphthalein pink. The following reaction takes place in aqueous solution,Example:  NH3 + H2O → NH4+ + OH-

A crop X grows well in slightly acidic soil. Which of the following substances can be added to the soil with pH = 8, in order to enhance the production of crop X?

One of the greatest observations of the father of soil chemistry was:Question 4Select one:A.all of the optionsB.ion exchangeC.effect of acidity in ion exchange when the soil is heatedD.Absorption of ions

Complete the following sentence: Lime (CaO) is added to water to produce slaked lime, Ca(OH)2. Slaked lime can be used to treat acidic soils. From this we can deduce that slaked lime is a ______

Which of the following is acidic in nature?(a) Lime juice(b) Human blood(c) Lime water(d) Antacid

Which of the following can increase the acidity of water bodies?a.Oil runoffb.Eutrophicationc.Sulfur discharge from an industryd.Hydrocarbon runoff from a refinery