Final answer:
The combined gas law is used to find that a gas with an initial volume of 380 cm³ at 27°C and 750 mmHg will have a volume of 1.332 liters at standard temperature and pressure (STP).
Step-by-step explanation:
To find the volume of a gas at standard temperature and pressure (STP), we can use the combined gas law, which is given by the relationship P1 x V1 / T1 = P2 x V2 / T2, where P is the pressure, V is the volume, and T is the temperature in Kelvin. Given that the gas initially has a volume of 380 cm³ at 27°C (300K) and 750 mmHg, we want to find the volume of the gas at STP, which is 0°C (273K) and 760 mmHg.
First, we convert the volume from cm³ to liters by dividing by 1000, and then we apply the combined gas law:
V2 = (P1 x V1 x T2) / (P2 x T1)
V2 = (750 mmHg x 0.380 L x 273K) / (760 mmHg x 300K)
V2 = (303,750 mmHg·L·K) / (228,000 mmHg·K)
V2 = 1.332 L
Therefore, the volume of the gas at STP would be 1.332 liters.