Question

(Please look at photo)Sort the molecular Compounds in the table and two groups with the same empirical chemical formula. That is, select group one next to all the compounds with the first empirical formula (If all four compounds have the same empirical formula, then they all end up in group one)Next, select group to next to all the compounds with a second empirical formula. And so on.If all four compounds have different empirical formulas, then they all each end up alone in their own group: Compound a will be alone in group one, compound be will be alone in group 2, and so on.About the sketches: The line stand for chemical bonds between atoms. Just ignore the dots. They stand for lone pairs and you’ll learn about them later you do not need to know anything about lone pairs to solve this problem.

Answer 1

Step 1 - Finding the molecular formulas for each compound

We can see each compound is made up of H, C and O atoms. Therefore, its molecular formula will be something like:

`H_xC_yO_z`

What we need to do to discover the full formula is counting the number of H, C and O atoms in the drawing. Let's do it for each compound:

`\begin{gathered} A\to12\text{ H, 6 C and 3 O} \\ \\ B\to6\text{ H, 6 C and 6 O} \\ \\ C\to\text{ 10 H, 5 C and 5 O} \\ \\ D\to\text{ 4 H, 4 C and 2 O} \end{gathered}`

The molecular formulas will be thus:

`\begin{gathered} A\to H_(12)C_6O_3 \\ \\ B\to H_6C_6O_6 \\ \\ C\to H_(10)C_5O_5 \\ \\ D\to H_4C_4O_2 \end{gathered}`

Step 2 - Finding the empirical formula for each compound

The empirical formula can be obtained by dividing the molecular formula by a number that divides all other numbers. We have to do this because in the empirical formula we express only the least possible proportion between the elements.

For example, in compound A, H12C6O3, all numbers (12, 6 and 3) are divisible by 3, therefore the empirical formula for A is:

`A\to H_4C_2O`

Doing the same for all others:

`\begin{gathered} B\to\text{HCO} \\ \\ C\to H_2CO \\ \\ D\to H_2C_2O \end{gathered}`

Step 3 - Sorting the compounds in groups

Since we have not obtained any compound with the same empirical formula, each compound belongs to its own group. Therefore we could sort it as:

`\begin{gathered} A\to\text{ group 1} \\ \\ B\to\text{ group 2} \\ \\ C\to\text{ group 3} \\ \\ D\to\text{ group 4} \end{gathered}`