Jul '09
MCAT Question of the Day | MCAT Course

  • Q:

    The molecular mass of KOH is 56. In a reaction with another compound X, 1 mol of KOH is added to 1 mol of compound X. Compound X has a molecular mass of 200. The matrix of the reaction is only water, and upon rotary evaporation, 238 grams of product are recovered. Assuming 100% recovery of the product and a 100% completed reaction, what is the most likely explanation for the mass discrepancy?



    The caustic solution reacted with compound X in such a way that volatile compounds were liberated and later evaporated


    The K+ replaced the H on -OH, allowing the H to react with OH- to form water which was evaporated


    Two OH- for each KOH reacted with compound X to give a mass of 238 grams


    There is no mass discrepancy; 238 is the maximum amount of product that can be recovered from the reaction

    Tags: Stoichiometry | Quantitative Skills | Suggest a tag


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