Acids and Bases
1) An acid is a substance which produces hydrogen ions (H+) when dissolved in water.
2) The main properties of acids are as follows.
4) An alkali is the solution formed when a base dissolves in water.
5) Alkalis produce hydroxide ions (OH-) when dissolved in water.
6) The main properties of alkalis are as follows:
H+ (aqueous) + OH- (aqueous) --> H20 (/)
8) The pH scale is used to determine if a given substance is acidic, alkaline or neutral.
9) The pH of colourless solutions can be determined using Universal Indicator.
10) It is important to control the pH of soil. Most plants grow best when the pH is around 7.
11) Quicklime (calcium oxide) and slaked lime (calcium hydroxide) are commonly used to reduce the acidity of soil.
12) Metals react with oxygen to form basic oxides or amphoteric oxides.
13) Non-metals react with oxygen to form acidic oxides or neutral oxides.
14) Basic oxides that are soluble in water are called alkalis.
15) Basic oxides that are insoluble in water are called insoluble bases.
(Refer to Manual Journal for more details and pictures of the set-ups)
2) The main properties of acids are as follows.
- They have a sour taste.
- They dissolve in water to form solutions which conduct electricity.
- They turn blue litmus paper red.
- They react with reactive metals to produce hydrogen gas and a salt.
- They react with carbonates to produce carbon dioxide gas, water and a salt.
- They react with metal oxides and hydroxides to produce a salt and water only.
4) An alkali is the solution formed when a base dissolves in water.
5) Alkalis produce hydroxide ions (OH-) when dissolved in water.
6) The main properties of alkalis are as follows:
- They have a bitter taste and a soapy feel.
- They turn red litmus paper blue.
- The produce ammonia gas when heated with ammonium salts.
- They react with a solution of one metal salt to give metal hydroxide and another metal salt.
H+ (aqueous) + OH- (aqueous) --> H20 (/)
8) The pH scale is used to determine if a given substance is acidic, alkaline or neutral.
9) The pH of colourless solutions can be determined using Universal Indicator.
10) It is important to control the pH of soil. Most plants grow best when the pH is around 7.
11) Quicklime (calcium oxide) and slaked lime (calcium hydroxide) are commonly used to reduce the acidity of soil.
12) Metals react with oxygen to form basic oxides or amphoteric oxides.
13) Non-metals react with oxygen to form acidic oxides or neutral oxides.
14) Basic oxides that are soluble in water are called alkalis.
15) Basic oxides that are insoluble in water are called insoluble bases.
(Refer to Manual Journal for more details and pictures of the set-ups)