7.1 Acids And Bases Flashcards
What is another name for oxonium
Hydronium
H3O+
Name 7 examples of acids
Hydrochloric
Nitric
Sulfuric
Sulfurous
Carbonic
Nitrous
Ethanoic
Formula of the following acids:
hydrochloric
Nitric
Sulfuric
Sulfurous
Carbonic
Nitrous
Ethanoic/acetic
HCl
HNO3
H2SO4
H2SO3
H2CO3
HNO2
CH3COOH
Name 3 strong acids+uses
Hydrochloric-stomach acid/clean metal surfaces
Nitric-fertilizer/explosives
Sulfuric-car batteries+paint
Name 4 weak acids+uses
Sulfurous-acid rain
Nitrous-atmosphere
Ethanoic-major compound in vinegar
Carbonic-fizzy drinks
Name 5 indicators + their colours in bases
Litmus- blue
Phenolphthalein- pink
Methyl orange - orange yellow
Thymolphthalein - blue
Bromothymol blue - blue
Name 5 indicators+their colours in acids
Litmus - red
Phenolphthalein - colour less
Methyl orange - pink/red
Thymolphthalein - colour less
Bromothymol blue - yellow
Acid reacting with metal
Acid + metal -> salt + hydrogen gas
Acid/metal reacting with bases(3)
Acid+base -> salt+water
Acid+metal oxide->salt+water
Metal+hydroxide=salt+water
Is a metal hydroxide an acid or a base
Base
Acid reacting with metal carbonate
Acid+metal carbonate->salt+carbon dioxide+water
Acid reacting with ammonia
Acid+ammonia->ammonium salt
What diprotic acids
Acids that have 2 hydrogens (protons) and are able to donate?
React with 2 waters to form 2 oxonium ions and the other ion has a -2 charge
What happens when acids react with water
They undergo a process called ionisation
The acid releases an H+ ion which joins to water to form an oxonium ion (positive)(the other ion will always be negative)
What is oxonium formula
H30+
(Always positive)
What are acids
Proton donors which produce an excess of H+ ions that react with bases to form water
What is responsible for the properties of acids+ the properties
The H+ ion
-Sour taste
-pH below 7
-Soluble in water
Why can acids form aqueous solutions
Because acids are soluble in water
4 examples of alkalis+formula+uses
NaOH- caustic soda-clean drains
KOH- caustic potash-defoam in manufacture of paper
NH4OH- cloudy ammonia-cleaning+manufacture HNO3
Ca(OH)2-lime water-improve soils, cement, neutralisation of acids
What is a base
Proton acceptors that react with H+ ions of acids to form water
(Any compound that can neutralize an acid)
Hydroxides/oxides of metals
What are alkalis+eg
Soluble bases which have an excess of OH ions
NaOH
Do bases always dissolve in water
No
Name 5 bases
Metal oxides
Metal hydroxides
Metal carbonate
Metal hydrogen carbonate
Ammonia solutions
What can be used to test pH
Universal indicator
What is the difference between strong and weak acids
Strong acids completely dissolve in water, meanwhile weak acids only partially ionise/dissociates in water+ are reversable
What is concentration
The quantity of solute dissolved in a litre of aqueous solution
What is
Concentrated acid
Dilute acid
A lot of acid, small volume of water
Small amount of acid, relatively large volume of water
Properties of alkalis
Soapy feeling
Turns litmus paper blue
Neutralizes acids
What does an acid and a base equal
Salt and water
What happens to alkalis in water
They dissociate to form hydroxide ions (OH-)
What are strong alkalis
Alkalis that dissociate completely in aqueous solutions
What are weak alkalis
Alkalis that partially dissociate in aqueous solution
What is the Brønsted-Lowry Theory
Defines acids and bases in terms of proton transfer between chemical compounds
What is a Brønsted-Lowry acid
A proton donor
Brønsted-Lowry base
A proton acceptor
What are amphoteric substances
2 eg.s
Substances that can act as both acids and bases depending on the reaction
Oxides that react with acids and bases to produce salt and water
ZnO
Al2O3
What is a conjugate acid
The substance forms when a base gains an H+ion
What is a conjugate base
Substance formed when an acid loses an H+ ion
What are the types of oxides + eg
Metal oxides-basic/alkaline producing CuO,CaO,NaOH,KOH
Non-metal oxides-acidic, produce acidic aqueous SO2,CO2
Amphoteric oxides Al2O3,ZnO
What are oxides called if they do not react + eg
Neutral
N2O,NO,CO
What is a neutral substance and neutralization (what do they do)
It doesn’t affect the colour of litmus paper
Chemical reaction between acid and alkali to produce a solution of salt and water
What are the 3 types of oxides
Metal oxides
Amphoteric oxides
Non-metal oxides
Features of metal oxides and 4 examples
Basic
Produce alkaline aqueous solution
1-copper oxide (CuO)
2-calcium oxide (CaO)
3-sodium hydroxide (NaOH_
4-potassium hydroxide (KOH)
What do metal oxides react with and what is the product
Acids, Salt and water
What are the features of non-metal oxides and 2 eg
Acidic
Produce acidic aqueous solutions
1-Sulfur dioxide (SO2)
2.-Carbon dioxide (CO2)
What do non-metal oxides reacts with and what is the product
Bases, salt and water
What are the features of amphoteric oxides +2 egs
Can be acidic or basic
1- Aluminium Oxide (Al2O3)
2.Zinc Oxide (ZnO)
What do amphoteric oxides react with and what is the product
Acid or bases
Salt and water
What does it mean if something is neutral/a neutral substance
Doesnt react with acid or base
Doesnt affect the colour of litmus paper
What is neutralisation
The reaction between an acid and a base to form a solution of salt and water
What are spectator ions
Ions that do not participate in chemical reactions and are present/remain the saame on both sides of the equations
4 examples of neutralisation reactions
Insect stings
Indigestion
Soil treatment
Tooth decay
Insect stings and what can neutralise them
Bee= acidic, baking soda (NaHCO3)
Wasp=basic, acetic acid/ vinegar (CH3COOH)
What is an alkali
A base that dissolves in water
What causes idigestion and what neutralises it
Excess HCl in the stomach
Antacids-milk of magnesia- Mg(OH)2,NaHCO3
Explain soil treatment
Plants like to grow in neutral soil, so quicklime(CaO), slaked lime (Ca(OH)2))or chalk (CaCO3)
Explain tooth decay and how it is neutralised
Bacteria produces an acid that eats the enamel on your teeth, toothpaste is an alkaline used to neutralise
What are neutral oxides+3 egs
Oxides that do not react with acids or bases
Nitrogen dioxide (N2O)
Nitrogen monoxide (NO)
Carbon monoxide (CO)
What is the mail neutralisation reaction
HCl+NaOH=HOH+NaCl
What salt does:
Nitric acid
Hydrochloric acid
Sulphuric acid
Produce
Nitrate
Chloride
Sulphate
What are salts
Compounds formed when the hydrogen atom in an acid is replaced by a metal from the base/alkali
How to you select a method of salt preparation
Decide whether the salt is soluble or insoluble
If soluble, then titration or crystallisation
If insoluble, then precipitation
What is the “formula” for titration and 3 common acids and the bases
Soluble acid+soluble base
HCl,H2SO4,HNO3
All the oxides
What are the apparatus needed for titration
Burette
Pippette
Safety burette filler
Conical flask
describe the process of titration
Pippette 25cm3 of acid into conical flask
Add a few drops of indicator to flask
Fill burette with alkali
Slowly add alkali to acid until colour changes
Repeat titration without indicator
Evaporation:heat solution until all water evaporates and only salt remains
Explain evaporation process
Solution is placed in a evaporating basin and is heated with a bunsen burner, the solution becomes more concentrated as it evaporates, once all the solution has evaporated, only the crystal solute will remain.
what is the water of crystallisation
Water molecules present in hydrated crystals
CuSO4
5H20
CoCl2
6H2O
What is a saturated solution
A solution that contains the maximun amount of solute that can be dissolved under the condition the solvent exhists.
What is the “formula” for crystallisation and 2 common compounds used
Insoluble base+acid
CuO, MgO
Describe the steps of crystallisation(6)
Add excess insoluble base to acid and allow to react
Separate excess solid from filtrate by filtration
Heat filtrate gently to form a saturated solution
Cool saturated solutions to allow for crystallisation
Dry the crystals between pages of filter paper
What are waters of crystallisations
Water molecules present in hydrated crystals
(Formulas separated by a dot) that can be hydrated to different degrees.
If there is no wtaer in the structure, it is an anhydrous compound, these can be formed/reversed by heating the hyrdrated compound
What is the “formula” for precipitation and what can be used(3)
Soluble+soluble->insoluble
AgNO3,PbNO3 or BaCl2
What are the steps for precipitation
Add solution(soluble salt) to AgNO3,PbNO3, BaCl2
Filter
Wash
Allow precipitate to dry on filter paper
What is ionisation of acids
When acids react with water and the acid releases an H+ which joins with water to from an oxonium ion.
What is an indicator
An organic dye which changes colour based on the change of H+ ions in a solution
Why do you repeat titration without the indicator
The indicator contaminâtes the salt, repeating it will allow for a pure salt.
Why do you add excess insoluble bases in crystallization
So that all of the insoluble base reacts with all the acid. You can filter out base, but not acid.
What is the difference between the products of crystallization and precipitation and how they are prepared
Crystallization forms crystals
Precipitation forms precipitate
Precipitate is washed, crystals arent
What metallic oxides acidic or basic?
Basic
Are non metallic oxides acidic or basic
Acidic
What is an ionic equation
An equation showing all the separate ions partaking in a reaction
What is the most common indicator used for titrations
Phenolphthalien
What does crystallisation form vs precipitation
Insoluble salt/crystal
Insoluble salt/base
What 3 compounds are solutions added to in precipitation
AgNO3
PbNO3
BaCl
What are the solubility rules(5)
- All common salts of the Group 1A elements and ammonium are soluble.
- All common acetates and nitrates are soluble.
- All binary compounds of Group VIIA elements (other than F) with metals are soluble except those of silver, mercury (1), and lead.
- All sulfates are soluble except those of barium, strontium, lead, calcium, silver, and mercury(1).
- Except for those in Rule 1, carbonates, hydroxides, oxides, and phosphates are insoluble
Describe an experiment to show that aluminum oxide is amphoteric
add a named acid, e.g. HCI and a named alkali, e.g. NaOH;
Al203 will react with /neutralises both reagents;
and so it will dissolve into the reagent /form a solution;
Physical properties of silicon (IV) oxide
high melting point/ high boiling point;
poor conductor (of electricity);
hard;
insoluble;
What oxides do metals form
Basic
What is an oxide
Chemical compound containing at least one oxygen atom and another element
Dissociation of ethanoic acid
Dissociation of HCL
HCl -> H+ +Cl-
What does an aqueous solution of acids contain
H+ ions
What does an aqueous solution of alkalis contain
OH- ions
Can acids and bases conduct electricity
Yes because they contain dissolved ions (they are electrolytes)
Base and ammonium salt reaction
Salt, ammonia gas and water
How does metallic character relate to oxides being acidic or basic
Metals are basic in nature, and metallic character decreases from left to right on the periodic table meaning the oxides become acidic as you move to the right
Hydrated substance
Substance that is chemically combined with water
Anhydrous substance
Substance containing no water
CuCl2 anhydrous and hydrated colours
Yellow
Green
