3.1.2 amount of substance Flashcards
1
Q
what is a mole?
A
an amount of substance
1 mole = 6.022x10^23
2
Q
how do you calculate the number of moles using Avogadro’s constant?
A
n = number of particles/6.022x10^23
3
Q
how do you calc moles with Mr and mass
A
n = mass (g) /Mr
4
Q
how do you calc moles in a solution?
A
n = concentration (moldm-3) x volume (dm-3)
5
Q
how do you calculate mass of a substance?
A
ensure equation is balanced
work out the mols of the given substance
use molar ratio to find mols of required
calculate mass of required using mols
6
Q
what is empirical formula?
A
the smallest whole number ratio of atoms of each element in a compound
7
Q
what is the molecular formula?
A
the actual number of atoms in a molecule
8
Q
what is the formula for percentage yield?
A
percentage yield = actual yield/theoretical yield x100
