Question

In order to determine the answer to a chemistry problem, a student first converted the given percentages to mole by assuming the sample size was 100 grams. Then the student divide by the smallest mole amount of the elements present. Finally the student used the ratios to write a formula. Which of the following best describes the problem the student likely solved?
a. Determined percent composition
b. None of the above
c. Determining molecular formula
d. Determining empirical formula

Answer 1

Answer: d. Determining empirical formula

Explanation:

Molecular formula is the chemical formula which depicts the actual number of atoms of each element present in the compound.  

Empirical formula is the simplest chemical formula which depicts the whole number of atoms of each element present in the compound.

Step 1: If percentage are given then we are taking total mass is 100 grams.  So, the mass of each element is equal to the percentage given.

Step 2 : convert given masses into moles

Step 3 : For the mole ratio, divide each value of moles by the smallest number of moles calculated

Step 4: The mole ratio gives the empirical formula of the compund.