How many moles of an unknown gas are in a 325 mL container at a pressure of 695 torr and 19 °C? A)9.42 B)1.48 × 10^-2 C)12.4 D)1.24 × 10^-2 E)80.6

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Quizplus · Accepted Answer

To find the number of moles of the gas, we can use the ideal gas law equation: PV = nRT, where P is the pressure in atmospheres, V is the volume in liters, n is the number of moles, R is the ideal gas constant (0.0821 L·atm/(mol·K)), and T is the temperature in Kelvin. First, we need to convert the given values to the correct units: 695 torr to atmospheres (1 atm = 760 torr), 325 mL to liters (1 L = 1000 mL), and 19 °C to Kelvin (K = °C + 273.15). Thus, P = 695 torr / 760 torr/atm = 0.9145 atm, V = 325 mL / 1000 mL/L = 0.325 L, and T = 19 °C + 273.15 = 292.15 K. Plugging these values into the ideal gas law equation and solving for n gives: n = PV / RT = (0.9145 atm * 0.325 L) / (0.0821 L·atm/(mol·K) * 292.15 K) ≈ 1.24 × 10^-2 moles.

How Many Moles of an Unknown Gas Are in a 325