Answer :

To determine the number of particles in 0.622 moles of a gas, you need to use Avogadro's number. Avogadro's number tells us that there are approximately [tex]\( 6.022 \times 10^{23} \)[/tex] particles in one mole of any substance.

Here’s the step-by-step calculation:

1. Identify the number of moles you have: 0.622 moles.
2. Use Avogadro's number which is [tex]\( 6.022 \times 10^{23} \)[/tex] particles per mole.
3. Multiply the number of moles by Avogadro's number to find the total number of particles:

[tex]\[ \text{Number of particles} = 0.622 \times 6.022 \times 10^{23} \][/tex]

When you perform this multiplication, you get:

[tex]\[ \text{Number of particles} \approx 3.745684 \times 10^{23} \][/tex]

Therefore, the number of particles in 0.622 moles of a gas is approximately [tex]\( 3.745684 \times 10^{23} \)[/tex].

So, the number of particles is [tex]\( \boxed{3.745684} \)[/tex].