Answer:
The law of conservation of mass states that matter can not be created or destroyed in a chemical reaction.
Explanation:
Procedures that are likely a chemical change are:
- Bubbles were produced when iron was placed in acid.
- Two liquids were combined, and a solid appeared
- A white substance turned blue when water was added.
During a phase change the temperature does not change since all of the heat is being absorbed in order to break the intermolecular forces. Due to that, the formula will not need to have T in it and is actually q=nΔH(v).
n=the number of moles (in this case 2.778mol of water since you divide 50g by 18g/mol).
ΔH(v)=the molar heat of vaporization (in this case 40.7kJ/mol).
q=the heat that must be absorbed
q=2.778mol×40.7kJ/mol
q=113.1kJ
Therefore the water needs to absorb 1.13×10²kJ.
I hope this helps. Let me know if anything is unclear.
It would be an physical change ; if you melt butter the butter goes from a solid to a liquid so therefore the physical state is changed.