The formula C2H4 can be classified as both a molecular formula
and an empirical formula. The answer is number 4.
The new volume of the bag will be 789.5 mL.
<u>Explanation:</u>
As per the Charles law, at constant pressure the volume of the gas is directly related to its temperature in Kelvin (K). That is as the temperature increases, the gas expands and vice-versa.

V1 = 250 ml
V2 = ?
T1 = 19° C
T2 = 60° C
Now we have to rewrite the equation to get the new volume as,
V2 = 
=
<em> </em>= 789.47 ≈ 789.5 ml.
So the new volume of the bag will be 789.5 mL.
Chemical Property
<u>Explanation:</u>
When a substance is changed into another substance, may be due to addition of some other substance or removal of water from that substance.
* its identity changes
*its reactivity changes
*reactivity towards water, air and many other substances will change
*its chemical composition changes
and all these changes occurs due to the chemical properties.
If the physical property changes then there will be change in the state of matter, but its boiling point, melting point , reactivity towards water, air and other substances will not change, and it will not lose its identity.