It would be a chemical change because the chloride water would have an effect on the copper. A way to tell if something is a chemical or physical change is that chemical change is not reversible. Physical change can be reversed. For example, water can be physically changed into ice, and it can go back into water. Hope this helps!
Answer:
The standard enthalpy of formation of ethanoic acid is -484 kJ/mol.
Explanation:
...[1]
..[2]
..[3]
The standard enthalpy of formation of ethanoic acid :
..[4]
Using Hess's law to calculate :
2 × [1] + 2 × [2] - [3] = [4]
The standard enthalpy of formation of ethanoic acid is -484 kJ/mol.
Any mechanical device which is used to help people is a (machine)
the answer is machine
Answer:
D. Crystallization
Explanation:
Let's clarify the irrelevant terms first.
- unification: This term has nothing to do with chemistry at all
- lithification: When the problem mentions magma and lava, you might think that this term is related to the process here. However, 'lithification' <em>do </em>have a precise meaning in geology. It refers to the process where sediments collapses into one single rock under pressure, which has nothing to do with the process mentioned here.
Now, for 2 terms that might confuse you: 'solidification' and 'crystallization' these also has precise scientific definition
Solidification is defined the process where substances in <em>liquid</em> phase changes its phase to <em>solid</em>. On first glance, this answer might seems correct, and yes, it is correct for this question. But not the <em>most</em> correct.
The keyword here is
'the internal components will arrange its self in an organized pattern.'
Crystallization is a special case of Solidification where the atoms or molecules of liquid solidify by spontaneously arrange themselves in periodic, ordered, and organized pattern. It might or might not happen during solidification depending on cooling rate, viscosity of liquid, and other factors.
So, Crystallization is the most correct answer here.
