Acids And Alkalis Flashcards
What does the skull symbol as a hazard symbol mean?
Toxic
What is a neutralisation reaction?
When an acid reacts with a base to produce a neutral solution of salt and water
If it is soluble in water, is it an alkali or base?
Alkali
If it is not soluble in water, is it a base or alkali?
Base
What is an alkali?
A base that is soluble in water
What does an indicator do?
Tells us the ph of a substance
Name 4 indicators
Litmus
Methyl orange
Phenolphthalein
Universal indicator
What’s a base?
A base is a substance that neutralises acids to form a salt and water only
Metal oxide + acid –> ? + ?
Salt + water
During neutralisation, how is water formed?
Hydrogen ions in acid combine with oxide ions to form water
During neutralisation, how is ph neutralised?
Through the removal of hydrogen ions
During neutralisation, how is salt formed?
By replacing the hydrogen ions with metal ions
What salt does hydrochloric acid form?
Chloride
What salt does sulphuric acid form?
Sulfate
What salt does nitric acid form?
Nitrate
What is used to prepare samples of different soluble salts?
An acid and insoluble metal oxide
What can an acid and insoluble metal oxide be used to do?
To prepare sample of different soluble salts
How can tin oxide be prepared?
By reacting tin(II)oxide with hydrochloric acid solution
In preparing soluble salts, what precaution is taken?
Excess of base is always added to ensure that all acid is used up
In preparing soluble salts, how is it made sure that the filtered salt is pure?
Mixture is filtered to remove unreacted metal oxide from the filtrate, leaving salt and water
In preparing soluble salts, how is a solid sample of the salt obtained?
Water evaporates, so crystallisation of the salt occurs
In preparing soluble salts, how is it made sure that the biggest amount of salt possible is formed?
Water is evaporated slowly, the slower it evaporates the larger the crystals that will form
What is concentration?
How many particles are dissolved in given volume of liquid
What does amount of hydrogen ions result in in terms of acidity?
The more acidic
What does the level of concentration result in in terms of pH?
Lower the concentration, the higher the pH
How do strong acids dissociate?
They completely dissociate (split up
How do weak acids dissociate?
Partially dissociate (only some split up)
What are the three strong acids?
Sulfuric acid, hydrochloric acid and nitric acid
What are the three weak acids?
Ethanoic acid, citrus acid, carbonic acid
What’s the formula of sulfuric acid?
H(little2)SO(little4)
What’s the formula of hydrochloric acid?
HCl
What’s the formula of nitric acid?
HNO(little3)
What’s the formula of ethanoic acid?
CH(little3)COOH
What’s the formula of citric acid
C(little6)H(little8)O(little7)
What’s the formula of carbonic acid?
H(little2)CO(little3)
What does a double headed arrow in a chemistry equation mean?
That it only partially dissociates
What charge will hydrogen always be?
Positive
How many acid particles do concentrated acids have dissolved in their water?
Lots of acid particles dissolved in the water
How many acid particles do dilute acids have dissolved in their water?
Only a few acid particles dissolved in the water
What is the equation for concentration?
Concentration= amount dissolved/volume
What’s the two SI units for concentration?
g/dm^3 or gdm-3
What’s SI units for amount dissolved (in concentration)?
g
What’s SI units for volume(in concentration)?
dm^3
1dm^3=?cm^3
1,000
What’s an acid?
A chemical that releases H+ions in water
What’s a base?
A base is any chemical that neutralises acids to make a salt and water only
What’s a neutralisation reaction?
A reaction that neutralises an acid
What does it mean for something to be neutral?
pH 7
What is pH?
Power of hydrogen, it is a measure of the concentration of H+ ions
What is concentration?
The number of particles per unit volume (g dm^3)
What does it mean if something is concentrated?
Lots of particles dissolved per unit volume
What does it mean for something to be dilute?
A few particles dissolved per unit volume
What is a weak acid?
Acid partially dissociated in water
What is a strong acid?
Acid fully dissociated in water
What type of scale is the pH scale? What does this mean?
It’s a logarithmic scale, meaning pH1 is 10 times stronger than pH 2
pH 1 IS 1000000 times stronger than pH6
What is an alkali?
A base that is soluble
What are the four soluble bases? (Alkalis)
Sodium hydroxide
Potassium hydroxide
Calcium hydroxide
Lithium hydroxide
What are the four insoluble bases?
Copper (II) hydroxide
Iron (III) hydroxide
Aluminium hydroxide
Copper (II) hydroxide
What does the (II) mean?
Charge of 2
What’s the formula of hydroxide ions?
OH-
What’s the sodium hydroxide formula?
Na+OH-
What’s the potassium hydroxide formula?
K+ OH-
What’s the calcium hydroxide formula?
Ca^2+ (OH-)2
What’s the lithium hydroxide formula?
Li+OH-
What’s the copper (II) hydroxide formula?
Cu+2 (OH-)(little2)
What’s the iron(III) hydroxide formula?
Fe+3(OH-)(little3)
What’s the sodium aluminium hydroxide formula?
Al+3(OH-)(little3)
What common ions have a +1 charge?
Hydrogen ion (H+), all group 1 metals
What common ions have a +2 charge?
Copper (Cu^2+) , all group 2 metals, zinc (zn ^2+)
What common ions have a +3 charge?
Aluminium (Al^3+)
What common ions have a -1 charge?
Chloride (Cl-) Bromide (Br-) Iodide (I-) Nitrate (No{little3}) Hydroxide (OH-)
What common ions have a -2 charge?
Sulphide (S^-2) Oxide (O^-2) Sulphate (SO{little4}^-2) Carbonate (CO{little2}^-2
H{little2}SO{little4}
What does the little 4 mean?
There’s 4 oxygen
SO{little4}2-
What is the charge?
-2
What is indigestion caused by?
Too much acid in the stomach
What do indigestion remedies do?
neutralises excess stomach acid
What are Rennie (indigestion) pills made of?
Calcium carbonate and Magnesium carbonate
In an experiment, what is an independent variable?
The thing you change
In an experiment, what is the controlled variable?
What you keep the same
In an experiment, what is the dependant variable?
What you want to find out
What do all acid solutions contain?
H^+
HCL > ?
H^+ CL^-
H(little2)SO(little4) > ?
2H+ SO(little4)^2-
CH(little3)COOH partially dissociates to ?
H^+ CH(little3)COO^-
What are the rules for big numbers in a formula
e.g.) 2HCl
The 2
Big number can only to at he start of the compound
2HCl
What does the 2 mean?
2 H, 2 Cl
H(little2)Cl
Wat does the little 2 mean?
2H, 1Cl
What do all alkali solutions contain?
OH-
NaOH(s) > ?
Na^+(aq) + OH^-(aq)
Ca(OH)(little2) > ?
Ca^2+ + 2OH^-
What is the equation that shows why a Neutralisation reaction makes water?
H^+ + OH^- > HHO
What is an acid alkali neutralisation?
A reaction in which hydrogen ions (H^+) from this acid react with hydroxide ions (OH^-) from the alkali to make water (H(little2)O)
What is the point of titration?
So we know how much acid is needed to neutralise the alkali so that when we do the experiment without the indicator we end up with pure salt and water with no indicator
When doing an experiment, how can you tell a gas is being released?
It will be bubbling
Magnesium + hydrochloride acid > ? + ?
Magnesium chloride + Hydrogen
How do you test for hydrogen?
It will make a ‘pop’ sound when you put a lot splint in it
What is CASHOCO?
Carbonate + Acid > Salt + H(little2)O + CO(little2)
In CASHOCO, what will Salt do?
Stay in excess at the bottom
In CASHOCO, what will CO(little2) do?
Form bubbles
How do you test for (COlittle2)
Add hydrochloric acid to carbonate. Test for it with bubbling gas produced through a delivery tube into lime water, which will go milky in colour .
Calcium carbonate + hydrochloric acid > ? + ? + ?
Calcium chloride + water + carbon dioxide
What is solubility?
A measure of how much of the substance will dissolve in a litre of water
What letter symbol in an equation do we use to say something is soluble in water?
aq
What letter symbol in an equation do we use to say something is insoluble in water?
s
Is all common sodium, potassium and ammonium salts soluble or insoluble in water?
Soluble
Is all nitrates soluble or insoluble in water?
Soluble
Is most chlorides soluble or insoluble in water?
Soluble
Is most Sulfates soluble or insoluble in water?
Soluble
Is sodium carbonate, potassium carbonate and ammonium carbonate soluble or insoluble in water?
Soluble
Is sodium hydroxide, potassium hydroxide, ammonium hydroxide soluble or insoluble in water?
Soluble
Is silver chloride, lead chloride soluble or insoluble in water?
Insoluble
Is lead sulphate, Borkum sulphate, Calcium sulphate soluble or insoluble in water?
Insoluble
Is most carbonates soluble or insoluble in water?
Insoluble
Is most hydroxides soluble or insoluble in water?
Insoluble
Sodium hydroxide (aq) + barium chloride (aq) > ? + ?
Sodium chloride (aq) + barium hydroxide (s)
