Scientists have known the consequences of mixing sodium bicarbonate and vitamin C ever since 1936, when a study on the subject was published in the "Journal of Nutrition." The authors of this study measured the amount of vitamin C recovered from the urine of people who drank a fixed amount of orange juice. The authors determined that the amount of vitamin C excreted was decreased by administration of sodium bicarbonate. Followup studies in the 1940s showed that this effect was due to the neutralization of the vitamin C by the sodium bicarbonate.
I won't give the answer, but here's the process: You have the weight of the object (0.500 lbs), and you want to convert that into the number of kernels. You are given the fact that 1 pound = 16 oz, and 1 oz=28.3 grams. So it should be apparent that you need to convert pounds to ounces first and then convert ounces to grams. Now that you the grams, you can easily figure out how many kernels there are because .125 grams equals the weight of one kernel.
Source: IGN