Question

How many carbon atoms are in 7.05 moles of pyridine

Answer 1

In 7.05 moles of pyridine there are
`(2.123).10^(25)` carbon atoms.

Step-by-step explanation:

The first step to solve this problem is to know the molecular formula of pyridine.

The molecular formula of pyridine is
`C_(5)H_(5)N`

This means that in one molecule of pyridine there are 5 atoms of carbon (C), 5 atoms of hydrogen (H) and 1 atom of nitrogen (N).

Also we can state the same relation between the atoms and the moles.

1 mole of pyridine contains 5 moles of carbon, 5 moles of hydrogen and 1 mole of nitrogen.

If we want to know how many carbon atoms are in 7.05 moles of pyridine we need to know how many atoms are in one mole.

The number of atoms in one mole of any substance is the Avogadro number.

The Avogadro number is
`(6.022045).10^(23)`

For example, in 1 mole of carbon there are
`(6.022045).10^(23)` atoms of carbon.

If we want to know the number of carbon atoms in 7.05 moles of pyridine we need to multiply :

`[(6.022045).10^(23)].(5moles).(7.05moles)=(2.123).10^(25)`

The first number is the Avogadro number

The second one is the number of carbon moles in one mole of pyridine

The third number is the number of moles of pyridine

We find that in 7.05 moles of pyridine there are
`(2.123).10^(25)` carbon atoms.

Answer 2

First, it is best to know the chemical formula of pyridine which is C5H5N. To determine the number of carbon atoms present in pyridine, multiply 7.05 mol C5H5N with 5 mol C/ 1 mol C5H5N which then results to 35.35 mol of carbon. Then, multiply the answer to Avogadro's number which is 6.022x10^23 atoms. It is then calculated that the number of carbon atoms in 7.05 moles of pyridine is 2.12x10^25 atoms.