Chapter 3: Amounts of substance Flashcards
Mole, Determination Formulae, Volumes
What is a mole?
A unit for describing 6.02E23 particles of a species per unit.
What is Avogadro’s constant?
6.02E23 particles per mole of carbon 12
What is the equation which derives moles?
n=m/Mᵣ
What is the equation to derive the number of particles of a substance?
Nbr= n · 6.02E23 (~Avga. const.)
What is the molecular formula?
The number of atoms of each element within a molecule.
What is the empirical formula?
The simplest ratio of elements in a molecule.
What is the relative formula mass?
The mass of a formula relative to 1/12th the mass of carbon-12
What are hydrated/hydrous salts?
Salts which contain water of crystallisation and thus are crystalised.
What are anhydrous salts?
Salts which do not contain any water of crystallization and thus are not arranged in a crystal structure as bonds are broken.
What is the water of crystallization?
Water trapped in crystals as salt crystals form. Lost through heating as bonds break releasing the water.
What is the molar volume of a gas at RTP?
24dm³mol⁻¹
What are the conditions of RTP?
293K (20°C) and 101 KPa (1 atm)
What is a standard solution?
A solution of known concentration.
What are the assumptions made in the ideal gas laws?
- Random motion of particles
- Elastic collisions
- Particles of negligible size
- No intermolecular forces
State the ideal gas equation with units…
pV=nRT P-Pa, V-m³, T-K, R-constant~8.314mol⁻¹K⁻¹
