How much MEKP is needed to initiate a cup of resin at 1% concentration?

To determine the correct amount of Methyl Ethyl Ketone Peroxide (MEKP) to initiate a cup of resin at a 1% concentration, we first need to understand the relationship between the resin volume and the percentage of the initiator being used.

In general, when you want to mix resin with a catalyst, such as MEKP, the concentration is expressed as a percentage of the total volume of resin. For example, if you are working with 250 ml of resin, calculating 1% of that volume will tell you how much MEKP is necessary.

1% of 250 ml is calculated as (1/100) * 250 ml = 2.5 ml. Thus, to achieve a 1% concentration of MEKP in the resin, 2.5 ml of MEKP is the correct amount to mix with 250 ml of resin.

This is consistent with the answer choice indicating 2.5 ml, highlighting the importance of understanding the concentration calculation in practical applications of using resins and catalysts in composite work.