Q = I × t : Quantity of Charge (Electricity) Calculations Tutorial
- A galvanic cell (voltaic cell) produces a flow of electrons.
This flow of electrons is called an electric current.
Current is given the symbol I and is measured in units of amperes (amps, A).
- The amount of charge passing a point in an electric circuit depends on the electric current and the time the current is allowed to flow for.
The amount of charge is given the symbol Q and is measured in units of coulombs (C).
- The quantity of charge (or electricity) contained in a current running for a specified time can be calculated:
Q = I × t
Q = quantity of charge (electricity) in coulombs (C)
I = current in amperes (amps, A)
t = time (seconds)
- This equation can be rearranged to calculate the electric current given quantity of charge (electricity) and time:
I = Q ÷ t
- This equation can be rearranged to calculate the time taken given the quantity of charge (electricity) and the electric current:
t = Q ÷ I
- This equation can be used to determine the quantity of charge, electric current, or length of time required to run an electrolysis experiment such as:
(i) for electroplating
Example from industry: electrorefining of copper