Final answer:
To find the density of HCl at STP, calculate its molar mass and apply the ideal gas law. The resulting density is 1.63 g/L, which is determined by dividing the molar mass by the molar volume of a gas at STP.
Step-by-step explanation:
Calculating the Density of HCl at STP
To calculate the density of hydrogen chloride (HCl) gas at standard temperature and pressure (STP), which is 0°C (273 K) and 1 atm (101.325 kPa), you can use the ideal gas law and the molar mass of HCl. The ideal gas law is PV=nRT, where P is pressure, V is volume, n is the number of moles, R is the ideal gas constant, and T is temperature.
- Calculate the molar mass of HCl by adding the atomic mass of hydrogen (1.01 g/mol) and chlorine (35.45 g/mol). The molar mass of HCl is thus 1.01 + 35.45 = 36.46 g/mol.
- Use the equation ρ = №(V/n) where ρ is density, № is molar mass, and (V/n) can be found from the ideal gas law at STP conditions.
- Since 1 mole of any gas at STP occupies 22.4 liters, the volume V/n for 1 mol is 22.4 L.
- Substitute known values into the equation and solve for density. The density of HCl at STP is ρ = (36.46 g/mol) / (22.4 L/mol) which equals 1.63 g/L.
Thus, the density of HCl gas at STP is 1.63 g/L.