Chemical species and Formulae Flashcards
What is a chemical species?
The smallest particle of a substance
What are the 4 types of chemical species giving examples of each:
- Atoms- metal atoms (K atoms)
- Molecules- non-metal atoms and non-metal compounds (Cl2 or H2)
- Ions- metal positive ions (cations) and non-metal negative ions (anions) (Na+ or Cl-)
- Molecular ions- multi-element ions (NH4+ or CO3 2-)
What do Roman numeral represent?
They indicate the positive charge of a named metal ion
What are ionic solutions and what do they contain?
Ionic compounds dissolved in water containing separate positive and negative ions
Which types of ionic compounds always dissolve in water?
Ionic compounds containing NO3-
What do acids do when dissolved in water?
Release H+ (aq) ions to form ionic solutions
How do we test for carbonate ions?
Add any acid (H+ ions)
Bubbles of colourless gas (CO2) is produced
CO3^2- + H+ -> CO2 + H2O
How do we test for sulfate ions?
Add barium chloride (Ba2+)
White precipitate-
BaSO4 (s)
How do we test for halide ions?
Add silver nitrate (Ag+)
Chloride ions-
White precipitate (AgCl)
Dissolves in dilute NH3
Bromide ions-
Cream precipitate (AgBr)
Dissolves in concentrated NH3
Iodide ions-
Yellow precipitate (AgI)
Does not dissolve in NH3
How do we test for ammonium ions?
Add a warm hydroxide (OH- ions) e.g NaOH
Bubbles of colourless gas (NH3) form which will turn damp red litmus paper blue
What is the formulae for the following non-metals: Carbon Hydrogen Oxygen Nitrogen Chlorine
C H2 O2 N2 Cl2
What is the formulae for the following non-metal compounds:
Water
Carbon dioxide
Ammonia
H2O
CO2
NH3
What is the formulae for the following acids:
Hydrochloric
Nitric
Sulphuric
HCl (aq)
HNO3 (aq)
H2SO4 (aq)
What is the formulae for the following ions and molecular ions: Group 1 Group 2 Group 7 Hydrogen Oxide Hydroxide Nitrate Sulfate Carbonate Ammonium Silver Zinc Nitride
X+ X2+ X- H+ O2- OH- NO3^- SO4^2- CO3^2- NH4^+ Ag+ Zn2+ Al3+ N3-
