Question

Mass, in grams, of 18.00 L of methane gas (CH4) at STP

Answer 1

The mass of 18.00 L of methane gas at STP is approximately 10.5744 g.

The molar mass of methane (CH4) is 16.0 g/mol. To find the mass of 18.00 L of methane gas at STP, we can use the ideal gas law: PV = nRT

where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature. At STP, the pressure is 1 atm and the temperature is 273 K. Rearranging the equation to find the number of moles:

n = PV/RT

Substituting the given values:

n = (1 atm)(18.00 L) / (0.0821 L atm/mol K)(273 K)

The number of moles of methane is approximately 0.6609 mol. Finally, to find the mass:

mass = n x molar mass

mass = (0.6609 mol) x (16.0 g/mol)

The mass of 18.00 L of methane gas at STP is approximately 10.5744 g.

Answer 2

12.83 g.

Step-by-step explanation:

At standard temperature and pressure (STP), which is defined as 0°C and 1 atm pressure, 1 mole of any gas has a volume of 22.4 liters.

Since the volume of methane gas is given as 18.00 L, we can calculate the number of moles by dividing the volume by the volume of one mole at STP:

18.00 L / 22.4 L/mol = 0.8 mol

The molar mass of CH4 is 16.04 g/mol, so we can calculate the mass of 0.8 mol of CH4 as follows:

0.8 mol * 16.04 g/mol = 12.83 g

So, the mass of 18.00 L of methane gas at STP is approximately 12.83 g.