Marcela dissolves 80.0 g of ammonium nitrate in 50.0 mL of water at room temperature and notes that the temperature of the solution decreases by 5.0°C.

Which correctly designates the signs of changes of G, S and H for this reaction? By changes the symbol is triangle. Please help me!!

AH>0, S>0 , G<0
BH<0, S>0 , G<0
CH>0, S>0 , G>0
DH<0, S<0 , G>0

On addition of the ammonium nitrate to 50 ml of water the temperature decreases which means that reaction between the ammonium nitrate and water is an endothermic reaction.The value of \(\Delta H\) is positive for an endothermic reactions.

\(\Delta H>0\)

Entropy is a degree of randomness of the system.

On addition of the ammonium nitrate to water ammonium nitrate break down into ions which means that entropy is increased.

\(\Delta S>0\)

\(\Delta G=\Delta H-T\Delta S\) (Gibb's free energy)

Since, ammonium nitrate is getting dissolved in water which means that this reaction is spontaneous and \(\Delta G\) of spontaneous reaction is negative that is:

\(\Delta G<0\)

sebassandin sebassandin · Answer 2 · 2019-11-03T16:29:10-05:00

Answer:

A. H>0, S>0 , G<0

Explanation:

Hello,

Based on the noticed change in temperature, one can identify that the enthalpy for this dissolution process is positive as long as the temperature decreases, so Δ\(H>0\).

Now, due to the fact of the bonds breaking down, one establishes that the entropy increases in a positive way, thus Δ\(S>0\).

Finally, by considering that the ammonium nitrate is being dissolved into the water a spontaneous process is carried out, implying that the change in Gibbs free energy turns negative, Δ\(G<0\), so one sum up that the answer is A.

Best regards.