Atomic structure Flashcards
What are the charges of each group in the Periodic table?
1 = +1 2 = +2 3 = +3 5 = -3 6 = -2 7 = -1
What is the definition and appearance of a solution?
A mixture containing a solute dissolved in a solvent - transparent
What is the definition and appearance of a precipitate?
Aqueous ions react together in aqueous solution to form a solid precipitate - opaque, solid substance
What is the definition of effervesence?
The release of gas from an aqueous solution
What should you say instead of “no visible change” while making an observation?
Stayed the same e.g. solution remained colourless
What is the formula for calculating relative atomic mass?
(mass of isotope A x % abundance) + (mass of isotope B x % abundance) / 100
What is the definition of relative isotopic mass?
The mass of an atom of an isotope compared with 1/12 of the mass of an atom of Carbon-12
What is the definition of relative atomic mass?
The weighted mean mass of an atom of an element compared with 1/12 of the mass of an atom of Carbon-12
What are the charges on zinc and silver ions?
Zn2+ and Ag+
What are the ions of ammonium, hydroxide, nitrate, carbonate, sulfate and phosphate (polyatomic ions)?
NH4(+) OH(-) NO3(-) CO3(2-) SO4(2-) PO4(3-)
What would the charges be on a Cu (ii) ion and an Fe (iii) ion?
Cu (ii) = 2+
Fe (iii) = 3+
How are binary (2 elements) compounds named?
Ending of the non-metal changed to -ide e.g. sodium chloride UNLESS it contains OXYGEN which means the ending would be -ate
How do you write formulae for ionic compounds?
Balance the charges on both ions
e.g. sodium oxide would be Na2O as Na has a + charge and O has a 2- charge
What is the chemical formula for iron (ii) nitrate?
Fe(NO3)2
What must you always do when writing ionic equations?
Include state symbols
What do ionic equations show?
The particular species that changes
e.g. AgNO3 + KBr –> AgBr (s) + KNO3 (aq)
AgBr is the precipitate so only Ag and Br are needed
Ag+ (aq) + Br- (aq) –> AgBr (s)
What type of reaction is Ag+ (aq) + Br- (aq) –> AgBr (s)?
Precipitation reaction
What do half equations show?
The loss/gain of electrons
e.g. Na –> Na+ + e-
Which compounds are all white and insoluble in solution?
BaCO3, Ag2CO3 and Ag2SO4
What is the correct sequence of tests?
- Carbonate test (removes carbonate ions)
- Sulfate test (removes sulfate ions)
- Chloride test
What would happen if you did the sulfate test first?
You would get 2 different white precipitates
- Ba(2+) + SO4(2-) –> BaSO4 (s)
- Ba(2+) + CO3(2-) –> BaCO3 (s)
What would happen if you did the chloride test first?
You could get 3 different white precipitates
- Ag+ + Cl- –> AgCl (s)
- 2Ag+ + SO4(2-) –> Ag2SO4 (s)
- 2Ag+ + CO3(2-) –> Ag2CO3 (s)
Which reagent is used to remove carbonate ions?
Nitric acid
Which reagent is used to remove sulfate ions?
Barium nitrate
Which reagent is used to remove chloride ions?
Silver nitrate
Which reagent is used to remove ammonium ions?
Sodium hydroxide + heat
