This question is describing the following chemical reaction at equilibrium:
![A\rightleftharpoons B](https://tex.z-dn.net/?f=A%5Crightleftharpoons%20B)
And provides the relative amounts of both A and B at 25 °C and 75 °C, this means the equilibrium expressions and equilibrium constants can be written as:
![K_1=\frac{90\%}{10\%}=9\\\\K_2=\frac{20\%}{80\%} =0.25](https://tex.z-dn.net/?f=K_1%3D%5Cfrac%7B90%5C%25%7D%7B10%5C%25%7D%3D9%5C%5C%5C%5CK_2%3D%5Cfrac%7B20%5C%25%7D%7B80%5C%25%7D%20%20%3D0.25)
Thus, by recalling the Van't Hoff's equation, we can write:
![ln(K_2/K_1)=-\frac{\Delta H}{R}(\frac{1}{T_2} -\frac{1}{T_1} )](https://tex.z-dn.net/?f=ln%28K_2%2FK_1%29%3D-%5Cfrac%7B%5CDelta%20H%7D%7BR%7D%28%5Cfrac%7B1%7D%7BT_2%7D%20-%5Cfrac%7B1%7D%7BT_1%7D%20%29)
Hence, we solve for the enthalpy change as follows:
![\Delta H=\frac{-R*ln(K_2/K_1)}{(\frac{1}{T_2} -\frac{1}{T_1} ) }](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5Cfrac%7B-R%2Aln%28K_2%2FK_1%29%7D%7B%28%5Cfrac%7B1%7D%7BT_2%7D%20-%5Cfrac%7B1%7D%7BT_1%7D%20%29%20%7D)
Finally, we plug in the numbers to obtain:
![\Delta H=\frac{-8.314\frac{J}{mol*K} *ln(0.25/9)}{[\frac{1}{(75+273.15)K} -\frac{1}{(25+273.15)K} ] } \\\\\\\Delta H=4,785.1\frac{J}{mol}](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5Cfrac%7B-8.314%5Cfrac%7BJ%7D%7Bmol%2AK%7D%20%2Aln%280.25%2F9%29%7D%7B%5B%5Cfrac%7B1%7D%7B%2875%2B273.15%29K%7D%20-%5Cfrac%7B1%7D%7B%2825%2B273.15%29K%7D%20%5D%20%7D%20%5C%5C%5C%5C%5C%5C%5CDelta%20H%3D4%2C785.1%5Cfrac%7BJ%7D%7Bmol%7D)
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Answer:
B) They are made up of particles that travel in a curved path when in motion.
Explanation:
We know that gas, being a state of matter, is made up of particles. John Dalton's solid-sphere model was proven to be incorrect by Ernest Rutherford's gold foil experiment.
These particles do NOT always move very slowly. There are multiple different factors that affect the speed of the particles such as temperature or concentration.
Explanation:
both iron and sulphur in FeS2 undergo a change in oxidation state.
O2° -->2O degree2- Total decrease = 2×2=4
So, 4FeS2+11O2 --> 2Fe2O3+8 SO2
Hence, balanced