What Is an Empirical Formula in Chemistry?

[megamu002]

I searched the internet for the answers and i keep coming up short maybe someone could help?




1. Which of the following is an empirical formula?
a) C5H10O5
b) C6H12O2
c) C12H17OH


Which of the following is an empirical formula?
NaO
C2H8N2
C6H3Cl2
What is the percent carbon in carbon dioxide?
12.01%
27.3%
44.009%

What is the percent nitrogen in potassium nitrate?
13.9%
101.1%
19.007%
Calculate the empirical formula for a compound that is 94.1% O and 5.9% H.
H2O
H2O2
HO2
HO

 

[mrjeffy321]

empirical formulas give the simplest whole number rations of the elements in a compound.
Take C5H10O5 for example, the ratio between Carbonydrogen:Oxygen is 5:10:5. This can be simplified to 1:2:1 and the ration remains the same, so we know this in a not an empirical formula. But on the other hand, of C12H17OH cannot be simplified without changing the ratio.

You might also want to have a look here,
http://www.chem.tamu.edu/class/majors/tutorialnotefiles/empirical.htm

 

[Blueshift5]

I would suggest using the principles of empirical formula calculations to solve these questions. The empirical formula is the simplest whole number ratio of atoms in a compound, and it can be determined by finding the mass percent of each element in the compound.

To find the empirical formula, you will need to know the mass or percent composition of each element in the compound. For example, to determine the empirical formula of a compound that is 94.1% oxygen and 5.9% hydrogen, you would first convert the mass percent to grams. This would give you 94.1 grams of oxygen and 5.9 grams of hydrogen.

Next, you would find the moles of each element by dividing the mass by the molar mass of the element. The molar mass of oxygen is 16 g/mol and the molar mass of hydrogen is 1 g/mol. This would give you 5.88 moles of oxygen and 5.9 moles of hydrogen.

Then, you would divide each mole value by the smallest mole value to get the mole ratio. In this case, the smallest mole value is 5.88, so you would divide 5.88 by itself to get 1 and divide 5.9 by 5.88 to get 1.003. This gives you a ratio of 1:1 for oxygen and hydrogen.

Based on this ratio, the empirical formula for this compound is HO, which is option D. I would suggest using this method to solve the other questions as well. I hope this helps!