The exception is the element<span> hydrogen. ... solid at room temperature (with the exception of mercury); usually shiny; </span>high<span> melting point; good conductor of ... could be </span>dull<span> or shiny; conducts heat and electricity, but not as well as metals ... allotropes–</span>Phosphorus<span>, Selenium and Carbon (in the form of graphite.) ...</span>
Answer: The enthalpy change for this reaction is 392 Joules
Explanation:
The balanced chemical reaction is,
![H_2(g)+CO_2(g)\rightarrow H_2O(g)+CO(g)](https://tex.z-dn.net/?f=H_2%28g%29%2BCO_2%28g%29%5Crightarrow%20H_2O%28g%29%2BCO%28g%29)
The expression for enthalpy change is,
![\Delta H=\sum [n\times B.E_{reactant}]-\sum [n\times B.E_{product}]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5Csum%20%5Bn%5Ctimes%20B.E_%7Breactant%7D%5D-%5Csum%20%5Bn%5Ctimes%20B.E_%7Bproduct%7D%5D)
![\Delta H=[(n_{H_2}\times B.E_{H_2})+(n_{CO_2}\times B.E_{CO_2})]-[(n_{H_2O}\times B.E_{H_2O})+(n_{CO}\times B.E_{CO})]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B%28n_%7BH_2%7D%5Ctimes%20B.E_%7BH_2%7D%29%2B%28n_%7BCO_2%7D%5Ctimes%20B.E_%7BCO_2%7D%29%5D-%5B%28n_%7BH_2O%7D%5Ctimes%20B.E_%7BH_2O%7D%29%2B%28n_%7BCO%7D%5Ctimes%20B.E_%7BCO%7D%29%5D)
where,
n = number of moles
Now put all the given values in this expression, we get
![\Delta H=[(1\times 1\times H-H)+(1\times 2\times C=O) ]-[(1\times 2\times O-H)+(2\times 1\times C-O)]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B%281%5Ctimes%201%5Ctimes%20H-H%29%2B%281%5Ctimes%202%5Ctimes%20C%3DO%29%20%5D-%5B%281%5Ctimes%202%5Ctimes%20O-H%29%2B%282%5Ctimes%201%5Ctimes%20C-O%29%5D)
![\Delta H=[(1\times 1\times 436)+(1\times 2\times 799) ]-[(1\times 2\times 463)+(2\times 1\times 358)]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B%281%5Ctimes%201%5Ctimes%20436%29%2B%281%5Ctimes%202%5Ctimes%20799%29%20%5D-%5B%281%5Ctimes%202%5Ctimes%20463%29%2B%282%5Ctimes%201%5Ctimes%20358%29%5D)
![\Delta H=392J](https://tex.z-dn.net/?f=%5CDelta%20H%3D392J)
Therefore, the enthalpy change for this reaction is 392 Joules
Answer:
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Explanation:
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Answer:
Sweets are sold loose, or pre-packed in 120g bags.
The 120 g bags are £1.49 each.
The loose sweets are £0.89 for 100g.
By calculating the price per gram, determine which is better value. Show your working.