Ionic Compounds And Analysis Flashcards
What is ionic bonding
Atoms transfer electrons to become positively of negatively charged ions
Which elements are most likely to form ionic bonds
An atom with just one or two electrons in the outer shell, they want to get rid of the electrons so they have a full outer shell
Atoms in group 6 and 7 which have nearly full outer shells so want to gain electrons to have a full outer shell
What is a cation
A positively charged ion
What is an anion
A negatively charged ion
What elements can form ionic bonds
A metal and non metal
What are the properties of ionic compounds
The ions form a closely packed regular lattice structure
Ionic bonds are very strong electrostatic forces of attraction between oppositely charged ions
They have high melting points because it’s hard to break the bonds between the ions
They conduct electricity when aqueous or molten because the ions separate and are free to move so can carry current but in solids they ions are held rigid so can’t move
What is the rule for naming a compound with two elements
Something - IDE
eg sodium + chlorine -> sodium chloride
What is the rule for naming compounds with three or more different elements
Something - ATE
Eg copper Sulfur and oxygen combine to get copper Sulfate
What is the formula for carbonate
CO3 ^2-
What is the formula for Sulfate
SO4^2-
What is the formula for hydroxide
OH-
What is the formula for nitrate
NO3-
What common substances are soluble
Common salts of sodium potassium and ammonium
Nitrates
Common chlorides
Common Sulfates
Sodium potassium and ammonium hydroxides and carbonates
What common substances are insoluble
Silver and lead chloride
Lead barium and calcium Sulfate
Carbonates and hydroxides
How to make a pure dry sample of an insoluble salt
Precipitation reaction
Add one spatula of lead nitrate to the test tube and fill with distilled water and shake
Do the same to one spatula of sodium chloride
Mix the two solutions and stir them up the lead chloride will precipitate out
Filter out the precipitate and wash with distilled water
Leave out the lead chloride to dry
How to get a pure dry sample of barium Sulfate
Mix the two soluble salts (barium nitrate and potassium Sulfate)
Filter out the precipitate
Wash with distilled water
Dry on filter paper
How is barium Sulfate used in medicine
It is opaque to X-rays so when drunk it shows up and can show blockages in the gut
Barium salts are toxic but barium Sulfate is insoluble so can safely be drunk because non is a absorbed into the body
This is known as a barium meal
What are the flame test colours
Sodium yellow orange
Potassium lilac
Calcium brick red
Copper blue green
How to do a flame test
Clean the wire look by dipping it in hydrochloric acid and rinsing with distilled water
Dip the clean wire loop into a sample of the compound put the wire in the blue part of the flame
What is the test for carbonates
You can test for carbon dioxide by bubbling through lime water and it will turn milk if co2 is present
So reacting the carbonate with an acid produces carbon dioxide gas
What is the test for Sulfates
add dilute HCL followed by barium chloride solution
a white precipitate of barium Sulfate means the original compound was a Sulfate
What is the test for chloride ions
Add dilute nitric acid followed by silver nitrate solution
A chloride will give a white precipitate of silver chloride
What is a spectroscopy
It used to identify elements in a sample the patterns of light emitted are different for each element
It is fast and reliable
It allowed scientists to discover new elements because new patterns of light were discovered
