Calculations Flashcards
1
Q
moles =
A
mass(g)/Mr
2
Q
% yield =
A
actual amount/expected amount x 100
3
Q
Q (energy change) (J) =
A
m(g) x C (4.2) x DeltaT
4
Q
DeltaH (molar enthalpy change) (kJ/mol)=
A
-Q/mols
5
Q
Concentration (moldm-3) =
A
mols/volume(dm3)
6
Q
Charge (C) =
A
current (A) x time (s)
7
Q
mols of e- =
A
charge (C)/96500
8
Q
96500C =
A
1 faraday = 1 mol of electrons
9
Q
Relative atomic mass (Ar) =
A
SUM(isotope mass x isotope abundance) / 100
10
Q
Relative formula mass (Mr) =
A
SUMAr
11
Q
How to work out empirical formula
A
Divide each element by their relative atomic mass
Divide by the smallest number of mols
12
Q
Energy change (can be Q or DeltaH) =
A
SUM(bonds broken) - SUM(bonds made)
13
Q
volume of a gas (dm3) =
A
mols of gas x 24
