If I connect 2 capacitors in:

1) parallel
2) series

in which is the charge across each capacitor the same and when does the charge differ?

For series connected capacitors, the charging current ( i_C ) flowing through the capacitors is THE SAME for all capacitors as it only has one path to follow.
Then, Capacitors in Series all have the same current flowing through them as i_C = i₁ = i₂ . Therefore each capacitor will store the same amount of electrical charge, Q on its plates regardless of its capacitance. This is because the charge stored by a plate of any one capacitor must have come from the plate of its adjacent capacitor. Therefore, capacitors connected together in series must have the same charge.

Q_C = Q₁ = Q₂

when the two capacitors are connected in parallel, the voltage across each capacitor is V, the same as that of the source, since they are connected directly to it through a conductor.  and as
Q=CV
with different capacitances, and the same potential difference will cause difference charge storage in each capacitor.

So, if you connect 2 capacitors in:
1) parallel
2) series

in series connection, is the charge across each capacitor the same, and in parallel combination, the charge differs.

_regards,