At STP (Standard Temperature and Pressure), the conditions are defined as a temperature of 0 degrees Celsius (273.15 Kelvin) and a pressure of 1 atmosphere (101.325 kilopascals). In order to determine the number of atoms present in a gas sample, we need to know the identity of the gas.
If we assume an ideal gas, we can use the ideal gas law to calculate the number of moles of gas present. The ideal gas law is expressed as:
PV = nRT
Where: P = pressure (in atmospheres) V = volume (in liters) n = number of moles R = ideal gas constant (0.0821 L·atm/(mol·K)) T = temperature (in Kelvin)
Rearranging the equation to solve for n, we have:
n = PV / RT
Substituting the given values into the equation, we have:
n = (1 atm) * (2.8 L) / [(0.0821 L·atm/(mol·K)) * (273.15 K)]
Calculating this expression, we find the number of moles of gas present in the given volume at STP.
Once we know the number of moles, we can use Avogadro's number, which is approximately 6.022 x 10^23 atoms per mole, to calculate the number of atoms.
Please provide the identity of the gas in order to proceed with the calculation.