Answer:
Molar mass of the substance
Answer:
W = -10.3 kJ
Explanation:
During combustion, the system performs work and releases heat. Therefore, the change in internal energy is negative, and the change in enthalpy, which is equal to heat at constant pressure, is also negative. Work is then calculated by rearranging the equation for the change in internal energy:
w=ΔE−qp=−5084.3 kJ−(−5074.0 kJ)
The release of heat is much greater than the work performed by the system on its surroundings. The potential energy stored in the bonds of octane explains why considerably large amounts of energy can be lost by the system during combustion.
Answer:
Electrons can jump from energy level to energy level (for example energy level 1 to 2) but they can NEVER be found in between energy levels.
Answer:
Rate constant k = 1.57*10⁻⁵ s⁻¹
Explanation:
Given reaction:
Expt [A] M [B] M Rate [M/s]
1 3.40 4.16 1.82*10^-4
2 4.59 4.16 3.32*10^-4
3. 3.40 5.46 1.82*10^-4
![Rate = k[A]^{x}[B]^{y}](https://tex.z-dn.net/?f=Rate%20%3D%20k%5BA%5D%5E%7Bx%7D%5BB%5D%5E%7By%7D)
where k = rate constant
x and y are the orders wrt to A and B
To find x:
Divide rate of expt 2 by expt 1
![\frac{3.32*10^{-4} }{1.82*10^{-4} } =\frac{[4.59]^{x} [4.16]^{y} }{[3.40]^{x} [4.16]^{y} }\\\\x =2](https://tex.z-dn.net/?f=%5Cfrac%7B3.32%2A10%5E%7B-4%7D%20%7D%7B1.82%2A10%5E%7B-4%7D%20%7D%20%3D%5Cfrac%7B%5B4.59%5D%5E%7Bx%7D%20%5B4.16%5D%5E%7By%7D%20%7D%7B%5B3.40%5D%5E%7Bx%7D%20%5B4.16%5D%5E%7By%7D%20%7D%5C%5C%5C%5Cx%20%3D2)
To find y:
Divide rate of expt 3 by expt 1
![\frac{1.82*10^{-4} }{1.82*10^{-4} } =\frac{[3.40]^{x} [5.46]^{y} }{[3.40]^{x} [4.16]^{y} }\\\\y =0](https://tex.z-dn.net/?f=%5Cfrac%7B1.82%2A10%5E%7B-4%7D%20%7D%7B1.82%2A10%5E%7B-4%7D%20%7D%20%3D%5Cfrac%7B%5B3.40%5D%5E%7Bx%7D%20%5B5.46%5D%5E%7By%7D%20%7D%7B%5B3.40%5D%5E%7Bx%7D%20%5B4.16%5D%5E%7By%7D%20%7D%5C%5C%5C%5Cy%20%3D0)
Therefore: x = 2, y = 0
![Rate = k[A]^{2}[B]^{0}](https://tex.z-dn.net/?f=Rate%20%3D%20k%5BA%5D%5E%7B2%7D%5BB%5D%5E%7B0%7D)
To find k
Use rate for expt 1:
![k = \frac{Rate1}{[A]^{2} } =\frac{1.82*10^{-4}M/s }{[3.40]^{2} } =1.57*10^{-5} s-1](https://tex.z-dn.net/?f=k%20%3D%20%5Cfrac%7BRate1%7D%7B%5BA%5D%5E%7B2%7D%20%7D%20%3D%5Cfrac%7B1.82%2A10%5E%7B-4%7DM%2Fs%20%7D%7B%5B3.40%5D%5E%7B2%7D%20%7D%20%3D1.57%2A10%5E%7B-5%7D%20s-1)
