Take note of the whole number beside each substance in the reaction because these will be used in the stoichiometric calculations below:
Molar mass of <span>k[ag(cn)2]:199 g/mol
Molar mass of Zn(Cn)2: 117.44 g/mol
Avogadro's number: 6.022</span>×10²³ molecules/mol
a.)
35.27 g*(1 mol/199 g)*(1 mol Zn(Cn)₂/ 2 mol K[Ag(CN)₂])*(6.022×10²³ molecules/mol) = <em>5.34×10²² molecules of Zn(Cn)₂</em>
b.)
35.27 g*(1 mol/199 g)*(1 mol Zn(Cn)₂/ 2 mol K[Ag(CN)₂])*(117.44 g/mol) = <em>10.41 g of Zn(Cn)₂</em>
Answer:

For temperatures higher than 533.49 K we will see a spontaneous reaction, and for temperatures lower than that the reaction will not be spontaneous.
Explanation:
When are chemical reactions spontaneous? To find out we need to look at the reaction's change in Gibbs Free energy:

When this is greater than zero, the reaction isn't spontaneous, when it is less than zero, we have a spontaneous reaction. The reaction must then change from spontaneous to non spontaneous when
. If we insert that into our equation we get:

That is the temperature at which the reaction's spontaneity will change, plugging in our values we find:

At that temperature we have
.
Now, at a temperature greater than this one, the entropy term in our equation for the Gibbs' free energy of reaction will take over, and make
, thus the reaction will be spontaneous.
On the other hand, if we lower the temperature, we will have a smaller entropy term, and we will have:
. That is, the reaction will not be spontaneous. Therefore for temperatures higher than 533.49 K we will see a spontaneous reaction, and for temperatures lower than that the reaction will not be spontaneous.
Answer: B.)
Explanation: Heat flows from pan to sounroundings
Answer:
q = -176kJ
Explanation:
HCl and NH3 reacts as following to NH4Cl
HCl(g) + NH3(g)=========>NH4Cl(s) : ΔH = -176 KJ
Clearly,
ENERGY IS EVOLVED MEANING IT IS A EXOTHERMIC REACTION .
therefore, the value of heat evolved as q = -176kJ