Section 4-Inorganic Chemistry P1 (pg41-50) Flashcards
acid + metal ->
salt + hydrogen
How does how a metal reacts with an acid tell you about the metals reactivity?
- the more reactive the metal, the faster the reaction will go
- very reactive metals react explosively
Describe an experiment which shows how metals reacting with acids can tell you information on the metal’s reactivity:
- set up three boiling tubes and fill them with equal volumes of dilute HCl
- place pieces of Mg, Zn, Fe in separate test tubes (keeping the size and shape the same)
- the speed of the reaction is determined by the rate at which bubbles of H are produced
- use the test for H to confirm it is H, the Mg should give off the loudest ‘squeaky pop’
metal + water ->
metal hydroxide + hydrogen
less reactive metal + steam ->
metal oxide + hydrogen
What metals don’t react with acids or water?
Metals from copper down in the reactivity series
below hydrogen in the reactivity series
The reactivity series:
Potassium Sodium Lithium Calcium Magnesium Aluminium CARBON Zinc Iron Lead HYDROGEN Copper Silver Gold
(Potato Soup Lives Cutely Mearly Always Cause Zoos In Leek Happily Complete Soup Group)
What is a displacement reaction/what happens?
In a displacement reaction, a more reactive metal will displace a less reactive metal from a compound.
-they are redox reactions
What happens when a metal carbonate decomposes?
Metal Carbonate –> Metal Oxide + Carbon Dioxide
What happens when a hydrated compound decomposes?
Hydrated Compound –> Anhydrous Compound + Water
When a metal reacts with water is an acid or alkaline formed?
An alkaline solution
If an element displaces a compound is it more or less reactive?
It’s more reactive
What happens if a displacement reaction occurs?
A change in temperature will happen
What do iron and steel corrode to make?
rust - rust is only used to describe the corrosion of iron
When does rusting happen?
when iron is in contact with oxygen and water
What type of reaction occurs when iron rusts?
oxidation reaction
- iron gains oxygen to form iron (III) oxide
- water then loosely bonds to it forming hydrated iron (III) oxide
What is the word equation for rusting?
iron + oxygen + water -> hydrated iron(III) oxide [rust]
What are the two main methods for preventing rusting?
Barrier methods
Sacrificial methods
What are the barrier methods for the prevention of rust?
- painting/coating with plastic - ideal for big or small structures (can be decorative too)
- oiling/greasing - used when moving parts are involved (like bike chains)
What are the sacrificial methods for the prevention of rust?
This involved putting a more reactive metal than iron with the iron
- zinc is often used, it is oxidised instead of the iron
- galvanising or big blocks of zinc blocks can be bolted to the iron (used on ship hulls, underground iron pipes)
What is galvanising?
Galvanising is when a coating of zinc is sprayed onto the object you are protecting by sacrificial methods
What do you remember for redox reactions?
OIL RIG (of elections)
O - oxidation
I - is
L - loss (of elections)
R - reduction
I - is
G - gain (of elections)
Define oxidation:
Oxidation is the gain of oxygen
Oxidation is the loss of electrons
An oxidisation reaction involves an oxidising agent
Define reduction:
Reduction is the loss of oxygen
Reduction is the gain of electrons
An reduction reaction involves a reducing agent
What’s the definition of pH?
pH-is the measure of the amount of hydrogen/hydroxide ions there are in a solution
-the pH scale goes from 0-14
What is the acid range on the pH scale?
pH0-6
red to yellow colours
What is neutral on the pH scale?
pH7
green
What is the alkali range on the pH scale?
pH8-14
blue to purple colours
What is an indicator?
A dye that changes colour depending on whether it is above or below a certain pH
What colour is phenolphthalein in an acid and in an alkaline?
Acid-colourless
Alkali-pink
What colour is methyl orange in an acid and in an alkaline?
Acid-red
Alkali-yellow
What colour is litmus in an acid and in an alkaline?
Acid- red
Neutral - purple
Alkali- blue
When a substance is more acidic what ion is increasing?
H⁺ Ions
When a substance is more alkaline what ion is increasing?
OH⁻ Ions
What’s a definition of an acid?
A substance that produces hydrogen ions in a solution.
A substance that donates a proton in a reaction.
What’s the definition of a base?
A substance that accepts a proton in a reaction, they can neutralise the acid
What the definition of an alkaline?
A substance that produces hydroxide ions in solution.
-alkalis are soluble bases
What’s a reaction between an acid and an alkali (a base) called?
A neutralisation reaction
What is the equation for a neutralisation reaction?
H⁺₍ₐᵩ₎ + OH⁻₍ₐᵩ₎ -> H₂O ₍ₗ₎
Acid + base —>
salt + water
What salt does hydrochloric acid produce?
Chloride salts
What salt does sulphuric acid produce?
Sulphate salts
What salt does nitric acid produce?
Nitrate salts
acid + metal oxide —>
salt + water
acid + metal hydroxide —>
salt + water
acid + ammonia —>
ammonium salt
acid + metal carbonate —>
salt + water + carbon dioxide
Are common acids soluble or insoluble?
Soluble
Are alkali bases soluble or insoluble?
Soluble
Are non alkaline bases soluble or insoluble?
Insoluble
Are nitrates soluble or insoluble?
Soluble
Are chlorides soluble or insoluble?
Most soluble except silver and lead chloride
Are sulphates soluble or insoluble?
Most are soluble except barium, lead(II) and calcium sulphate
Are carbonates soluble or insoluble?
Sodium, ammonium and potassium carbonates are soluble, all other carbonates are insoluble
Are hydroxides soluble or insoluble?
Sodium, potassium,calcium hydroxides are soluble, all others are insoluble
Are ammonium salts soluble or insoluble?
All are soluble
What do the rules of solubility tell you?
- if a precipitate will form (insoluble salt)
- if it will just form in solution (soluble salt)
How can you make a soluble salt?
use an acid and an insoluble base[or metal oxide or metal hydroxide] (both containing one of the ions you want)
Describe a practical for how to make a soluble salt:
- heat the acid in a water bath (speeds up the reaction) in a fume cupboard (removing acid fumes)
- add the base to the acid, producing a soluble salt (add the base to excess, you’ll know this when the excess base sinks to the bottom of the flask)
- filter off the excess solid (just have salt and water)
- heat the solution gently using a Bunsen burner to remove some of the water, then allow to cool and the salt to crystallise
