Your pre-reg has their GPhC registration exam this week, so you decide to give them two calculation questions to complete. After checking their answers, you inform them that unfortunately they have got both questions wrong.
Can you spot their errors and answer these questions correctly?
Question one: potassium permanganate strength
A patient is directed to use 40ml of a 1 in 8,000 solution of potassium permanganate each day for one week. The prescription directs you to make a solution 10 times this strength.
How much potassium permanganate, in micrograms, will be required to dispense this prescription?
Here is the pre-reg’s working out:
40ml x 7 days (one week) = 280ml of 1 in 8,000
10 times stronger, so must be 1 in 800