Question

Find the number of molecules in 100ml of Carbondioxide?

Answer 1

Find the number of molecules in 100ml of Carbondioxide?

In order to find the number of molecules of CO₂, we need to know number of moles.

At STP $\mathrm{v} = \mathrm{V} / \mathrm{V}_{\mathrm{m}}$

$\mathrm{V} = 0.1 \mathrm{~L}$

$\mathrm{V}_{\mathrm{m}} = 22.4 \mathrm{~L} / \mathrm{mol}$

$\mathrm{v}(\mathrm{CO}_{2}) = 0.1 / 22.4 = 0.0045 \mathrm{~mol}$

Then we have to use Avogadro's Law

$\mathrm{N}(\mathrm{CO}_{2}) = \mathrm{v}(\mathrm{CO}_{2}) * \mathrm{N}_{\mathrm{A}}$ $\mathrm{N}_{\mathrm{A}} = 6.02 * 10^{23} \mathrm{~mol}^{-1}$

$\mathrm{N}(\mathrm{CO}_{2}) = 0.0045 * 6.02 * 10^{23} = 2.71 * 10^{21}$

$\mathrm{N}(\mathrm{CO}_{2}) = 2.71 * 10^{21}$