How many moles of gas occupy 98 l at a pressure of 2.8 atmosphere and a temperature of 292 k

Let's assume that the gas has ideal gas behavior.

Then we can use ideal gas equation,
PV = nRT

Where, 
P = Pressure of the gas (Pa)
V = volume of the gas (m³)
n = number of moles (mol)
R = Universal gas constant (8.314 J mol⁻¹ K⁻¹)
T = temperature in Kelvin (K)

The given data for the gas is,
P = 2.8 atm = 283710 Pa
V = 98 L = 98 x 10⁻³ m³
T = 292 K
R = 8.314 J mol⁻¹ K⁻¹
n = ?

By applying the formula,
283710 Pa x 98 x 10⁻³ m³ = n x 8.314 J mol⁻¹ K⁻¹ x 292 K
                                       n = 11.45 mol

Hence, moles of gas is 11.45 mol.

This scenario is called diffusion. particles are moving from regions of high concentration to low concentration.

The dispersed phase is liquid and dispersed medium in milk is liquid