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!!

A. H>0, S>0 , G<0
B. H<0, S>0 , G<0
C. H>0, S>0 , G>0
D. H<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 [tex]\Delta H[/tex] is positive for an endothermic reactions.

[tex]\Delta H>0[/tex]

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.

[tex]\Delta S>0[/tex]

[tex]\Delta G=\Delta H-T\Delta S[/tex] (Gibb's free energy)

Since, ammonium nitrate is getting dissolved in water which means that this reaction is spontaneous and [tex]\Delta G[/tex] of spontaneous reaction is negative that is:

[tex]\Delta G<0[/tex]

sebassandin sebassandin · Answer 2 · 2019-11-03T22:29:10+01:00

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[tex]H>0[/tex].

Now, due to the fact of the bonds breaking down, one establishes that the entropy increases in a positive way, thus Δ[tex]S>0[/tex].

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[tex]G<0[/tex], so one sum up that the answer is A.

Best regards.