Ideal Gas Law Worked Chemistry Examples

Ideal Gas Law Worked Chemistry Examples You may wish to refer to the General Properties of Gases to review concepts and formulae related to ideal gasses. Ideal Gas Law Problem #1 Problem A hydrogen gas thermometer is found to have a volume of 100.0 cm3 when placed in an ice-water bath at 0 °C. When the same thermometer is immersed in boiling liquid chlorine, the volume of hydrogen at the same pressure is found to be 87.2 cm3. What is the temperature of the boiling point of chlorine? Solution For hydrogen, PV nRT, where P is pressure, V is volume, n is the number of moles, R is the gas constant, and T is temperature. Initially: P1 P, V1 100 cm3, n1 n, T1 0 273 273 K PV1 nRT1 Finally: P2 P, V2 87.2 cm3, n2 n, T2 ? PV2 nRT2 Note that P, n, and R are the same. Therefore, the equations may be rewritten: P/nR T1/V1 T2/V2 and T2 V2T1/V1 Plugging in the values we know: T2 87.2 cm3 x 273 K / 100.0 cm3 T2 238 K Answer 238 K (which could also be written as -35 °C) Ideal Gas Law Problem #2 Problem 2.50 g of XeF4  gas is placed into an evacuated  3.00 liter  container at 80 °C. What is the pressure in the container? Solution PV nRT, where P is pressure, V is volume, n is the  number  of moles, R is the gas constant, and T is temperature. P?V 3.00 litersn 2.50 g XeF4  x 1 mol/ 207.3 g XeF4   0.0121 molR 0.0821 l ·atm/(mol ·K)T 273 80 353 K Plugging in these values: P nRT/V P 00121 mol x 0.0821 l ·atm/(mol ·K) x 353 K / 3.00 liter P 0.117 atm Answer 0.117 atm