How many moles of argon are in 30.6L at 28K and 658 mmHg?

Answer : The number of moles of argon gas is, 11.5 mol

Explanation :

To calculate the moles of argon we are using ideal gas equation as:

where,

P = pressure of argon gas = 658 mmHg = 0.866 atm    (1 atm = 760 mmHg)

V = volume of argon gas = 30.6 L

n = number of moles of argon gas = ?

R = gas constant = 0.0821 L.atm/mol.K

T = temperature of argon gas = 28 K

Now put all the given values in the above formula, we get:

Therefore, the number of moles of argon gas is, 11.5 mol

a chemical reaction happens

explanation:

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3