Final answer:
The pressure of the gas will be approximately 92.8 mmHg.
Step-by-step explanation:
To find the pressure of the gas, we can use the combined gas law equation: P1V1 / T1 = P2V2 / T2, where P1 = 965.0 mmHg (initial pressure), V1 = 170.0 ml (initial volume), T1 = 25°C (initial temperature), V2 = 720.0 ml (final volume), and T2 = 298 K (final temperature).
Plugging in the values, we get:
(965.0 mmHg)(170.0 ml) / (25 + 273) K = P2(720.0 ml) / 298 K
P2 = [(965.0 mmHg)(170.0 ml) / (25 + 273) K] / (720.0 ml / 298 K) ≈ 92.8 mmHg
Therefore, the pressure of the gas will be approximately 92.8 mmHg.
The pressure of a gas when the volume is allowed to expand can be determined using the Combined Gas Law, which is a combination of Boyle's Law, Charles's Law, and Gay-Lussac's Law.
For a sample of methane (CH4) that occupies a volume of 170.0 ml at 25°C (which is 298 K) and exerts a pressure of 965.0 mmHg, to find the new pressure when the volume is expanded to 720.0 ml at the same temperature of 298 K, the Combined Gas Law formula is used:
P1V1/T1 = P2V2/T2