What is impedance?

What is the impedance of a pure inductance?

A capacitor and resistor are connected in series with an ac source. If the potential difference across C and R are 120 V and 90V respectively and if the rms current of the circuit is 3A, calculate (i) impedance and (ii) power factor of the circuit.

How much current is drawn by the primary of a transformer which steps down 220 volts to 22 volts to operate a device with an impedance of 220 Ω ?