C4 Stoichiometry Flashcards
define relative atomic mass (Ar) (1)
the average mass of naturally occurring atoms of an element on a scale where the ¹²C atom has a mass of exactly 12 units
define relative molecular mass (Mr) (1)
the sum of the relative atomic masses
what do the following state symbols stand for s,l,g,aq (4)
solid
liquid
has
aqueous
what is avogrado’s number (1)
6.02 * 10²³
what is a mole (1)
an amount of substance containing 6.02 * 10²³ particles
what is the equation that relates number of moles, mass and relative atomic / molecular mass (1)
number of moles = mass / relative atomic mass
what is the molar gas volume at room temperature
the number of moles that a gas occupies at room temperature and pressure is 24dm³
what is the equation that relates number of moles, volume and molar gas volume (1)
number of moles = volume / molar gas volume (24dm³)
how many cm³ are there in 1dm³ (1)
1000cm³ = 1dm³
how do you convert from cm³ to dm³ (1)
divide by 1000
what is the unit for concentration (2)
- g/dm³
- mol/dm³
what is the equation that relates number of moles, volume and concentration (1)
number of moles = volume * concentration
what are the steps for calculating reacting masses (5)
- identify the two substances in the equation
- write n, m, M underneath each one and fill in what you know
- calculate the number of moles for one of the substances
- consider the stoichiometric equations to calculate the number of moles of the other substances
- work out the mass / volume of the substances in question
what is limiting reactant (1)
the reactant that is used up first
what does it mean if a reactant is in excess (1)
there is more of it than needed to react with other reactant(s)
