2.1 Foundations in Chemistry Flashcards
Isotopes
Isotopes are atoms of the same element with a different mass number (different neutron number) and the same proton (and so electron number).
Relative atomic mass
Relative atomic mass is the weighted mean mass of an atom of an element compared to one-twelfth of the mass of an atom of carbon-12.
Relative isotopic mass
Relative isotopic mass is the mass of an atom of an isotope compared with one-twelfth of the mass of an atom of carbon-12
When do you use relative molecular mass and when do you use relative formula mass?
Relative molecular mass is used to describe simple molecules and relative formula mass is used to describe giant structures.
Molecular ions
Molecular ions are groups of covalently bonded atoms which can lose or gain electrons to form ions.
Amount of substance
Amount of substance is the quantity that has moles as its unit. Chemists use amount of substance as a way of counting atoms
Mole
A mole is the amount of any substance containing as many particles as there are carbon atoms in exactly 12g of the carbon-12 isotope.
Avogadro constant
The Avogadro constant, NA (A is on the bottom), is the number of atoms per mole of the carbon-12 isotope (6.02214076×10^23 mol−1) or 6.02…
Molar mass
Molar mass, M, is the mass per mole of a substance. The units of molar mass are g mol−1
Empirical formula
Empirical formula is the simplest way of showing a chemical formula. It shows the ratio between elements, rather than actual numbers of atoms of each element.
Avogadro’s hypothesis
Avogadro’s hypothesis stated that under the same conditions of temperature and pressure, a mole of any gas would fill the same volume of space
Molar gas volume
Molar gas volume is the volume per mole of a gas. The units are dm^3 mol-1. At RTP, the molar volume is approximately 24.0dm^3 mol-1.
Formula involving moles and gas volumes
n=v/V
Ideal gas equation
pV=nRT
How do you convert between atm and Pascals (main unit)?
1 atm = 101325 pascals
