Final answer:
To calculate the change in volume of a gas when the temperature and pressure change, we can use the ideal gas law equation: PV = nRT. Using the given values, we can solve for the final volume and find that it is 365 cm^3.
Step-by-step explanation:
To calculate the change in volume of a gas when the temperature and pressure change, we can use the ideal gas law equation: PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.
In this case, we can set up two equations using the given values:
Initial equation: 780 mmHg * 350 cm^3 = n * 0.0821 atm L/mol K * (25 + 273) K
Final equation: 740 mmHg * V = n * 0.0821 atm L/mol K * (30 + 273) K
Rearranging the final equation to solve for V, we get:
V = (780 mmHg * 350 cm^3 * (30 + 273) K) / (740 mmHg * (25 + 273) K) = 365 cm^3.
So, the volume occupied when the temperature is changed to 30°C and the pressure to 740 mmHg is 365 cm^3. Therefore, the correct option is (a) 365 cm^3.