Copy of Empirical Formula 2 (5/28/2026)

Last updated about 2 hours ago

4 questions

Copy of Empirical Formula 2 (5/28/2026)

Last updated about 2 hours ago

4 questions

Determine Empirical Formula:
Convert the percent composition to mass composition (assume you have 100.0 g of the sample and convert percentages to grams).
Convert the mass compositions to mole compositions (divide each mass composition by the atomic mass of the element).
Convert the mole compositions into a molar ratio by dividing each mole composition by the smallest mole composition of the group and then round each to the nearest whole number.
Use the mole ratio values as the subscripts for the empirical formula.
Step 1 - Percent Comp. → Mass Comp (Assume you have 100 g of the sample; 100% = 100g)


Step 2 - Mass Comp → Mole Comp (divide mass composition by atomic mass of the element)


Step 3 - Mole Comp → Mole Ratio (find the lowest mole composition from step 2 and divide all mole compositions by it; round to nearest whole number).


Step 4 - Mole Ratio → Empirical Formula (use mole compositions from step 3 as subscripts in the empirical formula).

Determine the empirical formula for the following compound:
92.3% carbon (C) and 7.7% hydrogen (H)

a.) Step 1 - Mass Compositions?
C = _______ g
H = _______ g

b.) Step 2 - Mole Compositions?
C = _______ mol
H = _______ mol

c.) Step 3 - Mole Ratios?
C = _______  
H = _______ 

d.) Step 4 - Empirical Formula = _______ 

Determine the empirical formula for the following compound:
10.13% carbon (C) and 89.87% chlorine (Cl)

a.) Step 1 - Mass Compositions?
C = _______ 
Cl = _______ 

b.) Step 2 - Mole Compositions?
C = _______ 
Cl = _______ 

c.) Step 3 - Mole Ratios?
C = _______ 
Cl = _______ 

d.) Step 4 - Empirical Formula = _______ 

Determine the empirical formula for the following compound:
55.8% carbon (C), 37.2% oxygen (O), and 7.0% hydrogen (H)

a.) Step 1 - Mass Compositions?
C = _______ 
O = _______ 
H = _______ 

b.) Step 2 - Mole Compositions?
C = _______ 
O = _______ 
H = _______ 

c.) Step 3 - Mole Ratios?
C = _______ 
O = _______ 
H = _______ 

d.) Step 4 - Empirical Formula = _______ 

Determine the empirical formula for the following compounds:

a.) 65.45% carbon (C), 5.45% hydrogen (H), and 29.09% oxygen (O)
Empirical Formula = _______ 

b.) 40.3% K, 26.7% Cr, and 33.0% O
Empirical Formula = _______ 

c.) 52.8% Sn, 12.4% Fe, 16.0% C, and 18.8% N
Empirical Formula = _______ 

d.) 32.0% C, 42.6% O, 18.7% N, and the remainder H
Empirical Formula = _______ 

e.) 31.9% K, 28.9% Cl, and the remainder H
Empirical Formula = _______ 

f.) 12.26% N, 3.54% H, 28.1% S, and 56.1% O
Empirical Formula = _______ 