Unit 2 - Foundations in Chemistry Flashcards
(28 cards)
Define the term ‘relative atomic mass.’
- The average mass of an atom
- Compared to 1/12 the mass
- Of an atom of C-12
Define what is meant by the ‘weighted mean mass.’
- The average mass
- Taking into account the relative abundancies of the isotopes
Define the term ‘relative isotopic mass.’
- The mass of an isotope
- Compared to 1/12 the mass
- Of an atom of C-12
Define the term ‘empirical formula.’
The simplest whole number ratio of atoms present in a compound
Define the term ‘molecular formula.’
The actual number of atoms of each element present in a compound
Define the term ‘hydrated salt.’
A salt that contains water of crystallisation
Define the term ‘anhydrous salt.’
A salt that contains no water of crystallisation
Define what is meant by the term ‘standard solution.’
A solution of a precisely known concentration
Define the term ‘acid.’
A proton donor
Define the term ‘base.’
A proton acceptor
Define what is meant by a ‘strong acid.’
- A proton donor
- That fully dissociates in solution
Define what is meant by a ‘weak acid.’
- A proton donor
- That only partially dissociates in solution
State one important use of ammonium sulfate.
Fertiliser
Apart from the manufacture of ammonium sulfate state two other large-scale uses of ammonia.
- Refrigeration
- Manufacture of explosives
State a hazard of hydrogen gas.
It is explosive
Define what is meant by the term ‘oxidation.’
Loss of electrons
Define what is meant by the term ‘reduction.’
Gain of electrons
Define the term ‘oxidising agent.’
The substance that is reduced in a redox reaction
Define the term ‘reducing agent.’
The substance that is oxidised in a redox reaction
Define the term ‘redox reaction.’
A reaction where one substance is reduced and another is oxidised
Define the term ‘alkali.’
A substance that releases OH ions in solution
Define the term ‘salt.’
When the H⁺ ion in an acid is replaced by a metal ion
Define what is meant by ‘a concordant.’
Titre values that agree within 0.1cm³
Define what is meant by;
- a ‘solute.’
- a ‘solvent.’
- a ‘solution.’
- A substance that is dissolved in a solvent
- A substance that can dissolve a solute
- A solute dissolved in a solvent
