You have 357 ml of chlorine trifluoride gas at 699 mmHg and 45 celsius what is the mass of the sample

To find the weight of the gas you need to find the number of moles of using ideal gas formula. Remember to change the temperature unit to Kelvin and the pressure to kpa or atm

PV=nRT

n = PV/RT

n = 699 mmHg * 0.1333kpa * 0.357 L / 8.314 kpa*L / mol*K * (45 + 273.15) K

n = 0.012 moles

weight = n * molecular weight

weght = 0.012 * 92.448 g/mol = 1.109 grams