Q.33E - Chemistry (OpenStax)

Question

Write the empirical formula for the following compounds:

Step-by-Step Solution

Answer

The empirical formula for the given compounds are as follows:

1. CH₂O
2. C₂H₄O

Step 1: Identifying the chemical formula for the compounds

Count the total number of similar kinds of atoms present in the entire compound. 

In compound (a) there are 2 carbon atoms, 4 hydrogen atoms, and 2 oxygen atoms. So, the chemical formula of the given compound is C₂H₄O₂

While, in compound (b), 4 carbon atoms, 8 hydrogen atoms, and 2 oxygen atoms are present in the entire compound. Hence, the chemical formula of the compound is C₄H₈O₂.

 

Step 2: Determining the empirical formula from the chemical formula

The empirical formula is the simplest whole-number ratio of atoms present in the chemical formula of a compound.

The chemical formula of compound (a) is C₂H₄O₂. The lowest common factor for 2,4 and 2 is 2. Dividing all the numerical values present in the chemical formula will result in the simplest ratio of 1,2 and 1. Hence, the empirical formula for compound (a) is CH₂O.

For compound (b), the lowest common factor is 2. The simplest whole ratio by dividing all the numerical values by 2 will be 2,4,1. Hence, the empirical formula for compound (b) is C₂H₄O.

 

Hence, the empirical formula for compound (a) is CH₂O and for compound (b) is C₂H₄O.