What is the phase angle between voltage and current in a purely capacitive circuit?

Current leads voltage (or voltage lags current) by 90° in a purely capacitive circuit. Try to remember it this way: capacitors resist change in voltage, hence the voltage lags (they resist voltage change because the voltage first goes to charging up the electric field in the capacitor).

Inductors resist change in current (energy in an inductor is in the form of magnetic fields, which are caused by the current through the wire). Remember an inductor is a coil (like an electromagnet, or a transformer).