Answer:
Br
Step-by-step explanation:
Given data:
Mass of gas = 0.239 g
Volume of gas = 100 mL
Pressure exerted by gas = 603 mmHg
Temperature of gas = 14 °C
What is gas = ?
Solution:
Volume of gas = 100 mL (100mL ×1 L/1000 mL= 0.1 L)
Pressure exerted by gas = 603 mmHg (603/760 = 0.79 atm)
Temperature of gas = 14°C ( 14+273 = 287 K)
The given problem will be solve by using general gas equation,
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
now we will calculate the number of moles.
n = PV/RT
n = 0.79 atm × 0.1 L / 0.0821 atm.L/ mol.K × 287 K
n = 0.079 /23.563 /mol
n = 0.003 mol
Molar mass of gas:
Number of moles = mass/molar mass
0.003 mol = 0.239 g/ molar mass
Molar mass = 0.239 g/ 0.003 mol
Molar mass = 79.7 g/mol
The molar mas of Br is 79.9 g/mol so it is closer to 79.7 thus given gas is Br.