A gas occupies 20 dm³at 30°c at 2.5 atm find its volume ayt s.t.p.

To find the volume of the gas at standard temperature and pressure (STP), we need to use the ideal gas law equation. The ideal gas law equation is:

PV = nRT

Where:
P = Pressure
V = Volume
n = Number of moles
R = Ideal gas constant
T = Temperature

First, let's convert the given values to their appropriate units.
The gas occupies 20 dm³, which can be converted to liters by multiplying it by 1 liter/1000 dm³.
So, the volume is 20 dm³ * 1 liter/1000 dm³ = 0.02 liters.

The temperature is given as 30°C. We need to convert it to Kelvin scale by adding 273.15.
So, the temperature in Kelvin is 30°C + 273.15 = 303.15 K.

The pressure is given as 2.5 atm.

Now, we can substitute the values into the ideal gas law equation and solve for the volume at STP.

For STP:
P = 1 atm (pressure at STP)
T = 273.15 K (temperature at STP)

Let's rearrange the equation to solve for V at STP:
V1 / P1 = V2 / P2

V2 = (V1 * P2) / P1
V2 = (0.02 liters * 1 atm) / 2.5 atm

V2 = 0.008 liters

Therefore, the volume of the gas at standard temperature and pressure (STP) is 0.008 liters.