Acid and Bases Flashcards
what is a acid?
it is a substance that produces hydrogen ions, H+, when dissolved in water
what is a strong acid?
it dissociates completely in water to produce hydrogen,H+, ions
what is a weak acid?
it dissociates partially in water to produce hydrogen,H+, ions
what are some properties of acids?
- produces hydrogen, H+, ions when dissolved in water
- turns blue litmus paper red
- tastes sour
- is corrosive
- turns green universal indicator red (strong acid) and orange (weak acid)\conducts electricity when dissolved in water
- has a PH less than 7
what are some examples of strong acids?
- sulfuric acid
- nitric acid
- hydrochloric acid
what is an example of a weak acid?
enthanoic acid
what is the product between the reaction of an acid and a metal?
salt + hydrogen
what is the product between the reaction of an acid and a metal carbonate?
salt + water + carbon dioxide
what is the product between the reaction of an acid and an alkali?
salt + water
what is the reaction between an acid and alkali called?
neutralisation
how to test for hydrogen gas?
- place a lighted splint at the mouth of the test tube containing the gas to be tested
- if the gas is hydrogen, the lighted splint will extinguish with a ‘pop’ sound
- effervescence observed
how to test for carbon dioxide gas?
- bubble the gas to be tested through a test tube containing lime water
- if the gas is carbon dioxide, a white precipitate will form
what are some uses of ethanoic acid?
vinegar
what is a base?
a substance that reacts with an acid to give salt and water
what is an alkali?
a substance that produces hydroxide ions, OH-, when dissolved in water
what is a strong alkali?
a substance that dissociates completely in water to produce hydroxide, OH-, ions
what is a weak alkali?
a substance that dissociates partially in water to produce hydroxide, OH-, ions
what are some properties of alkalis?
- produces hydroxide, OH-, ions
- turns red litmus paper blue
- tastes bitter
- feels slippery
- turns green universal indicator violet (strong alkali) and blue (weak alkali)
- conducts electricity when dissolved in water
- has a PH more than 7
what are some common examples of alkalis?
- sodium hydroxide
- potassium hydroxide
- calcium hydroxide
- ammonium hydroxide
what is the product between the reaction of an alkali and an acid?
salt + water
what is the product between the reaction of an alkali and a ammonium salt?
salt + water + ammonia gas
what are the polyatomic ions and their chemical formula?
- sulfate, SO4 2-
- carbonate, CO3 2-
- nitrate, NO3-
- hydroxide, OH-
- ammonium, NH4+
what is the chemical formula for ammonia gas?
NH3
how to test for ammonia gas?
- place a piece of moist red litmus paper at the mouth of the test tube containing the gas to be tested
- if the gas is ammonia, the moist red litmus paper will turn blue
what is a PH scale?
a set of numbers used to indicate whether a solution is acidic, neutral or alkaline
what can a PH scale be used for?
shows the strength of a acid or alkali
what are some indicators?
- universal indicator
- PH probe
what is the colour of acids in phenolphthalin?
colourless
what is the colour of alkalis in phenolphthalin?
pink
what is the colour of acids in methyl orange?
red
what is the colour of alkalis in methyl orange?
yellow
what is the colour of acids in litmus?
red
what is the colour of alkalis in litmus?
blue
how can we control soil PH?
- chemicals are used to adjust the PH value
- acidic soils are treated with bases such as quick lime (calcium oxide) or slaked lime (calcium hydroxide)
- this is known as ‘liming’ the soil
what are the two categories that oxides are differentiated with?
metal oxides
non-metal oxides
what are the two categories that non-metal oxides are differentiated with?
acidic oxides
neutral oxides
what are examples of neutral oxides?
CO
NO
H2O
what are the two categories that metal oxides are differentiated with?
basic oxides
amphoteric oxides
what are examples of amphoteric oxides
ZnO
Al2O3
PbO
what does a basic oxide react with and what is formed in the reaction?
acid and they produce salt and water
what does an acidic oxide react with and what is the product formed in the reaction?
bases and they produce salt and water
what does a neutral oxide react with and what are its properties?
nothing
show neither acidic or basic properties, being insoluble in water
what does a amphoteric oxide react with and what are its properties?
both acids and bases
behave as acids and alkalis, reacting with both acids and alkalis to form salt and water
