Physical. When you simply desolve something with water, to don't actually change it. This action can be undone.
An example of a chemical reaction is when the cells within completely change. You you burn wood, you can't go back in time and un-burn it. Does that make sense?
A electrochemical reaction is said to be spontaneous, if
Answer 1:
Consider reaction: <span>Ni^2+ (aq) + S^2- (aq) ----> + Ni (s) + S (s)
The cell representation of above reaction is given by;
</span>

Hence,

we know that,

and

Therefore,

= - 0.25 - (-0.47) = 0.22 v
Since,
is positive, hence cell reaction is spontaneous
.....................................................................................................................
Answer 2: Consider reaction: <span>Pb^2+ (aq) +H2 (g) ----> Pb (s) +2H^+ (aq)
</span>
The cell representation of above reaction is given by;

Hence,

we know that,

and

Therefore,

= - 0.126 - 0 = -0.126 v
Since,
is negative, hence cell reaction is non-spontaneous.....................................................................................................................
Answer 3:
Consider reaction: <span>2Ag^+ (aq) + Cr(s) ---> 2 Ag (s) +Cr^2+ (aq)
</span>
The cell representation of above reaction is given by;

Hence,

we know that,

and

Therefore,

= - 0.22 - (-0.913) = 0.693 v
Since,
is positive, hence cell reaction is spontaneous
The one with higher temperature is the one with NaOH as heatis given off during the neutralization reaction that occurs.
<h3>
What is volume?</h3>
Volume can be defined as the amount of space a substance or an objects occupies usually in a closed container.
Volume is measures in litres.
When water is added to dilute acid like HCl, they become more dilute.
When NaOH is added to HCl, a neutralization reaction occurs.
The student will determine the contents of the flasks by adding 10 ml of hcl to each flask. If the NaOH reacts with the Hcl, there will be an increase in temperature.
The increase in temperature is due to the heat of neutralization of the reaction between NaOH and HCl.
Learn more about volume at: brainly.com/question/1972490
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Answer:
i picked b
Explanation:
but its based on your own opinion, good luck.
The reason people describe water as a universal solvent is because it dissolves almost anything.