Answer:

Explanation:
Hello,
In this case, we can use the ideal gas equation:

So we know the temperature, pressure and volume, therefore we can easily compute the required moles as shown below:

Best regards.
Answer:
<em>Mass percent composition of K = mass contribution of K/molecular mass of K3Fe(CN)6 x 100% Mass percent composition of K = 117.30 g/mol/329.27 g/mol x 100% Mass percent composition of K = 0.3562 x 100% Mass percent composition of K = 35.62%</em>