MCAT Chemistry Questions — Iron Production
- Jan 19, 2015
- MCAT Blog, MCAT Chemistry, MCAT Question of the Day
Fe2+ is reduced to Fe using a current of 4 A for a total time of 96.5 seconds. How much iron metal will be produced in this time?
A) 10-6 g
B) 10-1 g
C) 102 g
D) 106 g
This question requires your understanding of metal formation through a chemical reduction. In this case, Fe2+ + 2 e– –> Fe. To determine the amount of iron that is produced in a given time provided the current, you must use Faraday’s constant and the molecular weight, as follows:
(4 C/s)(96.5 s)(1 mole e–/96,500 C)(1 mole Fe/2 mole e–)(55.8 g Fe/mole Fe) = 10-1 g
If you were unsure of how to go about solving for the iron produced, you may want to consider using dimensional analysis so that you can cancel out all units until you are left with grams of iron. B is the correct answer.
Want more MCAT practice?
We’ve got options for every schedule and learning style!
From the best online MCAT course created by top instructors with 524+ MCAT scores to the most representative full-length practice exams and private tutoring, we can custom tailor your MCAT prep to your goals!
Not sure which option is right for you? Schedule a free MCAT consultation with an MCAT Advisor using the form below. No obligation, just expert advice.
Search the Blog
Free ConsultationSchedule Now
MCAT Blog How to Review MCAT Full-Lengths
Free MCAT Practice AccountNeed great MCAT practice?
Get the most representative MCAT practice possible when you sign up for our free MCAT Account, which includes a half-length diagnostic exam and one of our full-length MCAT practice exams.Learn More