Acids, Bases and Salts Flashcards
Indicators
Substances which indicate whether compound is acidic or basic by change in colour
Natural Indicators
red cabbage extract, turmeric, hydrangea, litmus
Artificial Indicators
Mehtyl Orange, Phenopthalein
TURMERIC
yellow in color, remains yellow in acidic soln, turns red in basic soln
HYDRANGEA
blue in color, remains blue in acidic soln, turn pink in basic soln
METHYL ORANGE
red color in acidic soln, yellow color in basic soln
PHENOPTHALIEN
colorless, remains colorless in acidic soln, turns pink in basic soln
RED CABBAGE EXTRACT
red in color, remains red in acidic soln, turns green in basic soln
LITMUS
base- turns red litmus blue
acid- turns blue litmus red
OLFACTORY INDICATORS
indicate whether substance is acidic or basic in nature by changing odor or smell
VANILLA EXTRACT
characteristic smell remains as it is in acidic soln but cannot be detected in basic soln
Onion
characteristic smell remains as it is in acidic soln but cannot be detected in basic soln
EXAMPLES of OLFACTORY INDICATORS
vanilla extract, onion
ACIDS
sour in taste, conduct electricity
ORGANIC ACIDS
naturally occuring, weak in nature
EXAMPLES OF ORGANIC ACIDS (6)
Lactic Acid, Tartaric Acid, Oxalic Acid, Methanoic/formic, Acetic Acid, Citric Acid
LACTIC ACID
SOUR MILK/CURD
TARTARIC ACID
TAMARIND, UNRIPE GRAPES
OXALIC ACID
TOMATOES
methanoic acid is also known as
formic acid
Methanoic Acid
Ant’s sting, nettle leave sting
Citric Acid
citrus fruits like lemon, lime
Acetic Acid
Vinegar
MINERAL ACIDS
prepared from minerals of earth, man made, generally strong in nature
which mineral acid is not strong in nature
Carbonic acid (H2CO3)
three most used mineral acids
Sulphuric, Hydrochloric and Nitric
Acetic acid (in form of vinegar) is used in?
pickles, ketchup
Tartaric Acid is used in making
baking powder
carbonic acid is used in making
fizzy drinks
why should water be added gradually while diluting acid?
diluting acid is highly exothermic process–> lot of heat is produced
if water is added at once, large amount of heat would be evolved which would convert some of the water to steam, this might lead to acid splashing and causing burns
when acids react with metal
hydrogen gas is formed along with salt
example of metal reacting with acid
zinc + sulphuric acid —> zinc sulphate + hydrogen
Zn+H2SO4 —> ZnSO4+H2
why should food not be stored in metal containers?
because acid in food will react with metal to form harmful metal compounds
acid react with metal carbonate/hydrogen carbonate
to form salt, CO2, H2O
example of metal carbonate reacting with acid
sodium carbonate + hydrochloric acid—> sodium chloride + carbon dioxide+ water
Na2CO3 + 2HCl —> 2NaCl+ CO2+ H2O
metal carbonate/hydrogen carbonate + HCl (hydrochloric)
metal chloride+ CO2 + H2O
metal carbonate/hydrogen carbonate +H2SO4 (sulphuric)
metal sulphate + CO2 + H2O
example of metal hydrogen carbonate reacting with acid
sodium hydrogen carbonate + hydrochloric acid –> sodium chloride+ carbon dioxide + water
NaHCO3+HCl—> NaCl+CO2+H2O
lime water and carbon dioxide
Ca(OH)2 + CO2 —> CaCO3 + H2O
calcium hydroxide + carbon dioxide + calcium carbonate + water
lime water is
calcium hydroxide, Ca(OH)2
quicklime is
CaO, calcium oxide
slaked lime
Ca(OH)2