MCAT Question of the Day: Empirical Formula
March 6, 2014
Great work on today’s question!
The empirical formula of a compound is the simplest whole number ratio of the atoms in it, whereas the molecular formula represents the actual whole number ratio of the atoms. The molecular formula is usually a whole number multiple of the empirical formula, although sometimes the empirical and molecular formulas are the same.
Remember going through this question that it is asking for which of the statements are FALSE. Statement I is true. For example, water, H2O, has the same empirical and molecular formula. Statement II is false because it is the molecular formula which is usually whole number multiple of the empirical formula, not the other way around. Finally, statement III is false. H2O2, hydrogen peroxide, has an empirical formula of HO, so the empirical formula is different from the molecular formula given. Since statements II and III are incorrect, choice C is the answer we’re looking for!
Stay tuned next week for another question!
I am a former Kaplan MCAT student that excelled on my exam through the Kaplan methods and began teaching for Kaplan at the University of Illinois – Urbana – Champaign center. Upon graduation I moved back to the Chicagoland area and became a full time teacher in our Chicago centers. I really strive to bring enthusiasm and energy to the classroom believing a positive attitude sets the tone for success! When I am not teaching the MCAT, you can find me training for triathlons or picking which bow tie to wear next!