Hey there!
For this we will use the combined gas law:
[tex]\frac{P_{1}V_{1}}{T_{1}} = \frac{P_{2}V_{2}}{T_{2}}[/tex]
We are only using volume and temperature, however, so we can remove pressure.
[tex]\frac{V_{1} }{T_{1} } = \frac{V_{2} }{T_{2} }[/tex]
V₁ = 25 mL
T₁ = 300 K
T₂ = 600 K
Solving for V₂, plug in values:
[tex]\frac{23mL}{300K} = \frac{V_{2}}{600K}[/tex]
Multiply both sides of the equation by 600K.
46 mL = V₂
So, the chlorine gas will occupy a volume of 46 mL at 600 K.
Hope this helps!