Final answer:
To find the molar mass of the gas, apply the ideal gas law to find the number of moles and then divide the mass of the gas by the number of moles. After the calculation, choose the correct molar mass from the given options.
Step-by-step explanation:
To determine the molar mass of a gas sample using the information provided, you can use the ideal gas law, which is PV = nRT. Here, P is the pressure (3.5 atm), V is the volume (12.5 L), n is the number of moles, R is the ideal gas constant (0.0821 L·atm/(K·mol)), and T is the temperature (575K).
First, solve for n, the number of moles, using the rearranged ideal gas equation: n = PV/(RT). Substituting the values in, we get n = (3.5 atm × 12.5 L) / (0.0821 L·atm/(K·mol) × 575K), which calculates to the number of moles of gas. After finding n, the molar mass (M) is calculated using the mass of the gas (1.9 g) divided by the number of moles.
By performing the calculations, we can identify the correct molar mass from the multiple-choice options presented.