A gas in a 325 mL container has a pressure of 695 torr at 19 °C. There are _ _ mol of gas in the flask. A) 1.48 × 10^-² B) 12.4 C) 1.24 × 10^-² D) 80.6 E) 9.42

Question

Quizplus · Accepted Answer

First, we need to use the ideal gas law equation to solve for the number of moles of gas in the container:

PV = nRT

where P is the pressure in atm, V is the volume in L, n is the number of moles, R is the gas constant (0.08206 L·atm/mol·K), and T is the temperature in Kelvin.

Converting the given pressure to atm and the volume to L:

P = 695 torr / (760 torr/atm) = 0.914 atm
V = 325 mL / 1000 mL/L = 0.325 L

Converting the given temperature to Kelvin:

T = 19°C + 273.15 = 292.15 K

Plugging in these values and solving for n:

n = PV/RT = (0.914 atm)(0.325 L)/(0.08206 L·atm/mol·K)(292.15 K) ≈ 1.24 × 10^-2 mol

So there are approximately 0.0124 mol of gas in the flask, which is closest to choice C, 1.24 × 10^-2 mol.

A Gas in a 325 ML Container Has a Pressure