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

We first assume that this gas is an ideal gas where it follows the ideal gas equation. the said equation is expressed as: pv = nrt. from this equation, we can predict the changes in the pressure, volume and temperature. if the volume and the temperature of this gas is doubled, then the pressure still stays the same.