Question 4: The first one
Question 5: The fourth one
Question 6: The first one
Question 7: The third one
Answer:
for the given reaction is -99.4 J/K
Explanation:
Balanced reaction: 
![\Delta S^{0}=[1mol\times S^{0}(NH_{3})_{g}]-[\frac{1}{2}mol\times S^{0}(N_{2})_{g}]-[\frac{3}{2}mol\times S^{0}(H_{2})_{g}]](https://tex.z-dn.net/?f=%5CDelta%20S%5E%7B0%7D%3D%5B1mol%5Ctimes%20S%5E%7B0%7D%28NH_%7B3%7D%29_%7Bg%7D%5D-%5B%5Cfrac%7B1%7D%7B2%7Dmol%5Ctimes%20S%5E%7B0%7D%28N_%7B2%7D%29_%7Bg%7D%5D-%5B%5Cfrac%7B3%7D%7B2%7Dmol%5Ctimes%20S%5E%7B0%7D%28H_%7B2%7D%29_%7Bg%7D%5D)
where 
represents standard entropy.
Plug in all the standard entropy values from available literature in the above equation:
![\Delta S^{0}=[1mol\times 192.45\frac{J}{mol.K}]-[\frac{1}{2}mol\times 191.61\frac{J}{mol.K}]-[\frac{3}{2}mol\times 130.684\frac{J}{mol.K}]=-99.4J/K](https://tex.z-dn.net/?f=%5CDelta%20S%5E%7B0%7D%3D%5B1mol%5Ctimes%20192.45%5Cfrac%7BJ%7D%7Bmol.K%7D%5D-%5B%5Cfrac%7B1%7D%7B2%7Dmol%5Ctimes%20191.61%5Cfrac%7BJ%7D%7Bmol.K%7D%5D-%5B%5Cfrac%7B3%7D%7B2%7Dmol%5Ctimes%20130.684%5Cfrac%7BJ%7D%7Bmol.K%7D%5D%3D-99.4J%2FK)
So, for the given reaction is -99.4 J/K
Answer: 
Explanation:
Electrolysis of a subastance is breaking it into its constituents by the action of electrical current.
In the electrolysis of molten sodium chloride, sodium metal is produced at the cathode which is a negative electrode and chlorine gas produces as the anode which is a positive electrode.
At anode :
At cathode : 
Answer:
-56.1kJ/mol
Explanation:
The reaction between HCl and NaOH is:
NaOH + HCl → NaCl + H₂O + ΔH
<em>Where ΔH is heat change in the reaction.</em>
<em />
As the temperature of the solution increases, the heat is released and ΔH < 0
The heat released in the reaction is obtained using coffe-cup calorimeter equation:
Q = C×m×ΔT
<em>Where Q is heat</em>
<em>C is specific heat of the solution (4.184J/g°C)</em>
<em>m is mass of solution: Assuming density = 1g/mL, 100mL of solution = 100g</em>
<em>And ΔT is change in temperature (13.4°C)</em>
<em />
Replacing:
Q = C×m×ΔT
Q = -4.184J/g°C×100g×13.4
Q = -5606.6J
Now, in the reaction you have:
<em>Moles HCl:</em>
0.050L * (2.2mol/L) = 0.11 moles
<em>Moles NaOH:</em>
0.050L * (2.0mol/L) = 0.1 moles
That means the moles of reaction are 0.1 moles, and heat change in the chemical reaction is:
5606.6J / 0.1 mol = 56066J =
<h3>-56.1kJ/mol</h3>
<em />
