True, is the correct answer.
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 answer is C Becuz D is a compound and that is the only answer that says it
You put in a variable to substitute the unknown number.
The cost of one antacid is 2.325 cents per tablet.
<u>Explanation:</u>
As per the question based on the student analysis we know that,
Total antacid tablets in a bottle = 120
Purchase Price of a bottle = $ 2.79
Cost of 1 antacid tablet
As we know $1 = 100 cent
The cost of 1 antacid tablet =
× 100 cents = 2.325 cents/tablet
.
Thus we came to know that it costs 2.325 cents/tablet
.