Question

I would like to know for the 1st column if I’m doing it right. Can you show me the steps for column 1 so I can double check the rest of the column answer. Appreciated

Answer 1

So,

We're going to assume a 100g mass of substance, and then interrogate the molar quantities of each element. The steps that we're going to follow, are:

Step 1. Divide the percentage of each element by its molecular mass: (These are the moles)

`\begin{gathered} C\colon \\ (63.3)/(12)=5.275 \\ H\colon \\ (7.2)/(1.00784)=7.1439 \\ N\colon \\ (2.2)/(14)=0.15714286 \\ O\colon \\ (27.3)/(16)=1.70625 \end{gathered}`

Step 2. We're going to divide each result by the smallest, in this case, it is 0.157.

`\begin{gathered} C\to(5.275)/(0.15714286)=33.56 \\ H\to(7.1439)/(0.15714286)\approx47 \\ N\to(0.15714286)/(0.15714286)=1 \\ O\to(1.706265)/(0.15714286)=10.85 \end{gathered}`

Now, approximate to the nearest number.

Finally, we obtain:

`C_(34)H_(47)NO_(11)`

The mass of this compound is 645.315g/mol. So, the empirical and molecular formulas are the same.