Acids, Bases and Salts

Activity . The reactions occurring in the above Activity are written as – Test tube A: Na CO HCl(aq) Cl(aq) H O(l) + CO (s) Na (g) Test tube B: NaHCO HCl(aq) Cl(aq) H O(l) + CO (s) Na (g) On passing the carbon dioxide gas evolved through lime water, Ca(OH) CO H O(l) (aq) (g) CaCO s ( ) (Lime water) (White precipitate) n Place a few pieces of granulated zinc metal in a test tube. n Add mL of sodium hydroxide solution and warm the contents of the test tube. n Repeat the rest of the steps as in Activity . and record your observations. The reaction that takes place can be written as follows. 2NaOH(aq) + Zn(s) → Na ZnO (s) + H (g) (Sodium zincate) You find again that hydrogen is formed in the reaction. However, such reactions are not possible with all metals.