Different quantities of nitrogen oxide (NO) are listed below - VCE - SSCE Chemistry - Question 3 - 2007 - Paper 1

This part is straightforward: it contains exactly $6 \times 10^3$ molecules, which equals 6000 molecules.

To find the number of molecules in 6 x 10² g of NO, we first need to determine the number of moles. The molar mass of NO is approximately 30 g/mol. Thus:

$n = \frac{6 \times 10^2 \text{ g}}{30 \text{ g/mol}} = 20 \text{ mol}$

Then, the number of molecules is:

$20 \text{ mol} \times 6.02 \times 10^{23} \text{ molecules/mol} \approx 1.20 \times 10^{25} \text{ molecules}$

From the definition, 6 moles of any substance contains:

$6 \text{ mol} \times 6.02 \times 10^{23} \text{ molecules/mol} \approx 3.612 \times 10^{24} \text{ molecules}$