3.4 ACIDS Flashcards
What colour does methyl orange turn in an acid
Red
What colour is methyl orange in alkali and neutral
Yellow
What color is phenolphthalein in an acid and neutral
Colourless
What colour is phenolphthalein in an alkali
Pink
What colour would a strong acid be on universal indicator
Red
What would a weak acid be on universal indicator
Yellow
What colour is neutral on a universal indicator scale
Green
What would a weak alkali be on universal indicator
Blue
What would a strong alkali be on universal indicator
Purple
Define the term acid
A H+ Donor
Define the term alkali
A OH- donor
Acid + Base = ?
Salt + Water
Acid + Metal = ?
Salt + Hydrogen
What is the formula for ammonium
NH4+
What is the formula and charge for hydroxide
OH-
What is the formula and charge for nitrate
NO3-
What is the formula and charge for carbonate
CO3 (2-)
What is the formula and charge for sulphate
SO4 (2-)
What is the difference between alkalis and bases
Alkalis are soluble and bases aren’t
Acid + Carbonate = ?
Salt + Water + Carbon Dioxide
What is the test for hydrogen
A lit splint will make a squeaky pop in hydrogen
What is the concentration of nitrogen in the air
78%
What is the concentration of oxygen in the air
21%
What is the concentration of argon in the air
0.96%
What is the concentration of carbon dioxide in the air
0.04%
How do you measure the concentration of oxygen in the air
By reacting it with another metal and finding the decrease in volume of air
What are the 2 common faults of the experiment of finding the concentration of oxygen in the air
1) Wasn’t given enough time to react
2) There was a leak in the apparatus
Metal + Oxygen = ? (+State)
Metal oxide (Solid)
Non-Metal + Oxygen = ? (+State)
Non-Metal dioxide (Solid)
What is a unique observation of magnesium and oxygen
Bright white light, and white powder formed
What is the unique observation of sulphur and oxygen
Blue flame
Charge of Silver
+
Charge of zinc
2+
Charge of Copper
2+
Charge of lead
2+
What is the test for oxygen
A glowing splint will relight in a test tube
What do metal oxides become when dissolved in water
alkaline soloution
What do non-metal dioxides become when dissolved in water
Acidic soloution
How do you determine whether an unknown element was a metal or non-metal
1) Combust it in oxygen
2) Dissolve the oxide formed
3) Check the pH of the solution with an indicator
Define a base
H+ Acceptor
What is the formula for ammonia
NH3
What is the formula for hydrochloric acid
HCl
What is the formula for nitric acid
HNO3
What is the formula for sulphuric acid
H2SO4
What is the formula for phosphoric acid
H3PO4
What is the formula for carbonic acid
H2CO3
What is the formula for ammonium hydroxide
NH4OH
Define a polyatomic ion
An ion that contains more than one ion
What salts are completely soluble
Sodium, Potassium, Ammonium and nitrate
What is chloride insoluable with
Silver and lead
What is sulphate insoluble with
Calcium, Barium and lead
What is carbonate soluble with
Sodium, potassium and ammonium
What is hydroxide soluable with
Sodium, potassium and calcium
What is oxide soluble with
Sodium, potassium and ammonium
What are 2 observations from an acid+Metal reaction
The metal disappears and effervescence
What 3 metals are too reactive to do a metal+acid reaction
Potassium, sodium and lithium
What 3 metals aren’t reactive enough to do a metal+acid reaction and why
Copper, silver and gold as they are less reactive than hydrogen
What is the only observation of a acid+base reaction
The base is used up in the reaction
What are the 4 stages to making a salt crystal
1) Add the base to an acid and heat it
2) Filter out excess base
3) Heat the salt solution until crystals start to form on the outside
4) Leave the salt solution to crystallize
What are the two observations of an acid Carbonate reaction
The carbonate disappears and effervesence
Acid + Ammonia –> ?
Ammonium Salt
Acid + Hydroxide –> ?
Salt + Water
Acid + Metal Oxide –> ?
Salt +Water
What colour does red litmus turn in acids
Red
What colour does red litmus turn in a neutral substance
Red
What colour does red litmus turn in alkalis
Blue
What colour does Blue litmus turn in acids
Red
What colour does Blue litmus turn in a neutral substance
Blue
What colour does blue litmus turn in alkalis
Blue
Why shouldn’t litmus paper be used alone to determine is a solution is acidic or alkali
1) It doesn’t give an indication of of how acidic or alkalinic it is and so universal indicator should be used as well
2) It stays the same colour in neutral substances as well
Non-metal oxides dissolved in water form what
Acidic soloutions
Metal oxides dissolved in water form what
Alkaline Solutions
What colour is copper powder when combined with oxygen
Black