Question

What mass, in grams, of bromine gas (Br2) is contained in a 15.7-liter tank at 24.6 degrees Celsius and 0.986 atmospheres? Show all of the work used to solve this problem.
Use PV=nRT
R = 0.0821 L atm/mol K

Answer 1

PV = nRT

P is pressure, V is volume, n is number of moles, R is the gas constant, T is temperature in K

(2.85 atm)(12.5 L) = (n)(.08206)(27 C + 273)

n = 1.45 moles x 35.45 grams / mol Cl2 = 51.3 grams

Answer 2

Answer: The mass of bromine gas contained is 101.15 grams.

Explanation:

To calculate the mass of bromine gas, we use the ideal gas equation, which is:

PV = nRT

where,

P = pressure of the gas = 0.986 atm

V = Volume of the gas = 15.7 L

n = Number of moles of gas = ? mol

R = Gas constant = $0.0821\text{ L atm }mol^{-1}K^{-1}$

T = temperature of the gas = $24.6^oC=(273+24.6)K=297.6K$

Putting values in above equation, we get:

$0.986atm\times 15.7L=n\times 0.0821\text{L atm }mol^{-1}K^{-1}\times 297.6K\\\\n=0.633mol$

To calculate the mass of bromine gas, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Molar mass of bromine gas = 159.8 g/mol

Moles of bromine gas = 0.633 mol

Putting values in above equation, we get:

$0.633mol=\frac{\text{Mass of bromine gas}}{159.8g/mol}\\\\\text{Mass of bromine gas}=101.15g$

Hence, the mass of bromine gas contained is 101.15 grams.