Answer : The enthalpy change for the reaction is, 97.7 kJ
Explanation :
According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.
According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.
The given main chemical reaction is,
The intermediate balanced chemical reaction will be,
(1) 
(2) 
(3) 
Now we are multiplying reaction 1 by 2 and reversing reaction 3 and then adding all the equations, we get :
(1) 
(2)
(3) 
The expression for enthalpy of main reaction will be,
Therefore, the enthalpy change for the reaction is, 97.7 kJ
Answer:
0.3936 J/gC
Explanation:
using the formula: q=mcΔt
q= 7032J
m=812g
ΔT = 22C
plug in and solve:
7032=(812)(c)(22)
c=7032/(812)(22)
c=0.39 J/gC
1. First, you have to find the number of moles 1.6z10^5L of gas is at 373K and 0.967atm using PV=nRT solving for n. (n=PV/RT). Everything is in the correct units and we know R is going to be 0.08206atmL/molK since it is a constant.
n=(0.967atmx160000L)/(0.08206atmL/molKx373K)
n=5054.8mol gas
Then you have to find the the number grams which can be found using the molar mass given as 29g/mol. multiply 29g/mol by the number of moles of gas we found in the previous step.
5054.8molx29g/mol=146589.9g of gas
Lastly, to find the density of the gas you need to divide the mass of the gas by its volume.
146589.9g/160000L=0.916g/L
2. The dinsity of the gas at STP should be higher than the density of gas with the given conditions. This is due to the fact that the given conditions involves a higher temperature than that of at STP which will cause the gas to expand therefore increasing the volume with out increasing the mass. The reason why the pressure is not building up even though the pressure is higher is that the balloon is not sealed meaning the gas can maintain about atmospheric pressure while expanding since the excess are just leaves the balloon.
the answer to part 2 can be proven by the fallowing:
To find the density of the gas at STP you first multiply the molar volume of gas at STP by the number of moles of gas from part 1 to get the volume of the gas at STP.
5054.8molx22.4L/mol=113228L
Then you divide the mass form part by the new volume to get the new density.
<span>146589.9g/113228L=1.30g/L</span>
I hope this helps. Let me know in the comments if any of it is unclear.
