Chemical Formulae, Equations and Calculations Flashcards
What elements must be written as molecules in balanced chemical equations?
H2, N2, O2, F2, Cl2, Br2, I2
What is the relative atomic mass?
the mass number (Ar) - the bigger number
What is the relative formula mass?
sum of the mass number of all elements in the compound
What is a mole?
a unit for the amount of a substance
What is the empirical formula?
the simplest ratio of elements in a compound
What is the molecular formula?
the formula of elements in a compound
What is water crystalisation?
the water molecules incorporated within a crystal lattice.
What do you call salt crystals with water and vice versa?
hydrated crystals and anhydrous crystals
What is the process of removing/adding water to a crystal?
hydration and dehydration
What is concentration?
the amount of a substance per unit volume of it
What are RTP conditions?
room temperature and pressure
they are used when doing gas volume equations at RTP conditions
What are the RTP conditions for temperature and pressure?
temperature: 25°C (298K)
pressure: atmospheric pressure (1)
What is the molar volume of any gas at RTP?
24dm³/24000cm³
What is the stoicmetric ratio?
the big numbers in a balanced chemical equation.
simplifying the ratio helps you find the ratio of moles of another element which you need for calculations.
What are the 4 state symbols?
(s), (l), (g) and (aq)
