Disconnected vs Connected parallel plate capacitor

[plindle]

I am having a hard time understanding the whole idea behind and the difference between disconnected vs connected parallel plate capacitor in terms of voltage and charge. How does this relate to the formula C(Q/V)=ke0A/d?

 

[sophiecentaur]

I am having a hard time understanding the whole idea behind and the difference between disconnected vs connected parallel plate capacitor in terms of voltage and charge. How does this relate to the formula C(Q/V)=ke0A/d?

The words alone don't have an unique message. What you (and we) would need is a circuit diagram of the two states you want to discuss.
What is certain is that, when a Capacitor is connected across a Voltage source (battery etc.) the PD across it is determined by the source volts. If the capacitor is being charged via a Resistor, the PD is determined by the (perhaps instantaneous) charge on the capacitor.
The Capacitance is determined by the dimensions of the capacitor (and stays the same) and the Charge will be CV, whatever V happens to be across it.