Answer: The pressure of the container will be 0.796 atm.
Step-by-step explanation:
To calculate the mass of bromine gas, we use the ideal gas equation, which is:
PV = nRT
where,
P = pressure of the gas = ? atm
V = Volume of the gas = 7.5 L
n = Number of moles of gas = [0.125 + 0.125] = 0.25 mol
R = Gas constant =
![0.0821\text{ L atm }mol^(-1)K^(-1)](https://img.qammunity.org/2019/formulas/chemistry/high-school/etwhi2epvrb0vgf8gtitily4ir9apx7ye7.png)
T = temperature of the gas =
![18^oC=(273+18)K=291K](https://img.qammunity.org/2019/formulas/chemistry/high-school/tdfx2saio2vaxeovm64k52x45d7d2s0n52.png)
Putting values in above equation, we get:
![P* 7.5L=0.25mol* 0.0821\text{ L atm }mol^(-1)K^(-1)* 291K\\\\P=0.796atm](https://img.qammunity.org/2019/formulas/chemistry/high-school/helg2y13elx6bc2yb991sfyuwee0xbzor4.png)
Hence, the pressure of the container will be 0.796 atm.