from this reaction equation:
Cu + Cl2 → CuCl2
so 1 mol CuCl2 will produce from 1 mol Cl2
when the moles of CuCl2 = mass / molar mass
= 25.4 g / 134.45 g/mol
= 0.189 moles
∴0.189 moles of CuCl2 will produce from 0.189 moles Cl2
∴ Volume of 0.189 moles of Cl2 is :
V = nRT/P
when n is the number of moles = 0.189 moles
R is ideal gas constant = 0.0821
T temperature in Kelvin = 18 + 273 = 291 K
P is the pressure = 2.13 atm
by substitution:
∴ V = 0.189 * 0.0821 * 291 / 2.13
= 2.12 L
