Question

. If 0.357 g of CH4 gas is introduced into an evacuated 1.75 L flask at 25°C, what is the pressure in

.08206 L atm/mol K)​

Answer 1

To find the pressure of CH4 gas in a flask, one must convert the mass of methane to moles, plug it into the Ideal Gas Law equation (PV = nRT), and solve for pressure. After calculation, the pressure of the methane gas at 25°C in a 1.75 L flask is approximately 0.33 atm.

Step-by-step explanation:

To calculate the pressure of CH4 gas in a flask using the Ideal Gas Law, you need to use the amount of substance (in moles), the volume of the container, the temperature, and the ideal gas constant in appropriate units. First, convert the mass of CH4 to moles by dividing by the molar mass of methane (16.04 g/mol). Then, use the Ideal Gas Law formula PV = nRT to solve for pressure (P).

Moles of CH4 = 0.357 g / 16.04 g/mol = 0.02226 mol

Given: V = 1.75 L, T = 25°C (which is 298.15 K when converted to Kelvin), R = 0.08206 L atm/mol K

Now, substitute the values into the Ideal Gas Law equation:

P = (nRT) / V

P = (0.02226 mol * 0.08206 L atm/mol K * 298.15 K) / 1.75 L

P = 0.3298 atm

Therefore, the pressure of CH4 gas in the flask at 25°C is approximately 0.33 atm.

Answer 2

P = 0.29 atm

Step-by-step explanation:

Given data:

Mass of CH₄ = 0.357 g

Volume of flask = 1.75 L

Temperature = 25°C ( 25+273 = 298 K)

R = 0.08206 L. atm/K.mol

Pressure = ?

Solution:

Number of moles :

Number of moles = mass/ molar mass

Number of moles = 0.357 g /16g/mol

Number of moles = 0.02 mol

PV = nRT

P = nRT/V

P = 0.02 mol × 0.08206 L. atm/K.mol. × 298 K / 1.75 L

P = 0.5 L. atm / 1.75 L

P = 0.29 atm