Answer:
Initial pressure = 157 kpa (Approx)
Explanation:
Given:
final temperature = 234 K
final pressure = 210 kpa
Initial temperature = 175 K
Find:
Initial pressure
Computation:
Initial pressure / Initial temperature = final pressure / final temperature
Initial pressure / 175 = 210 / 234
Initial pressure = 157 kpa (Approx)
Answer: ΔH for the reaction is -277.4 kJ
Explanation:
The balanced chemical reaction is,

The expression for enthalpy change is,
![\Delta H=\sum [n\times \Delta H(products)]-\sum [n\times \Delta H(reactant)]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%28products%29%5D-%5Csum%20%5Bn%5Ctimes%20%5CDelta%20H%28reactant%29%5D)
![\Delta H=[(n_{CCl_4}\times \Delta H_{CCl_4})+(n_{HCl}\times B.E_{HCl}) ]-[(n_{CH_4}\times \Delta H_{CH_4})+n_{Cl_2}\times \Delta H_{Cl_2}]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B%28n_%7BCCl_4%7D%5Ctimes%20%5CDelta%20H_%7BCCl_4%7D%29%2B%28n_%7BHCl%7D%5Ctimes%20B.E_%7BHCl%7D%29%20%5D-%5B%28n_%7BCH_4%7D%5Ctimes%20%5CDelta%20H_%7BCH_4%7D%29%2Bn_%7BCl_2%7D%5Ctimes%20%5CDelta%20H_%7BCl_2%7D%5D)
where,
n = number of moles
Now put all the given values in this expression, we get
![\Delta H=[(1\times -139)+(1\times -92.31) ]-[(1\times -74.87)+(1\times 121.0]](https://tex.z-dn.net/?f=%5CDelta%20H%3D%5B%281%5Ctimes%20-139%29%2B%281%5Ctimes%20-92.31%29%20%5D-%5B%281%5Ctimes%20-74.87%29%2B%281%5Ctimes%20121.0%5D)

Therefore, the enthalpy change for this reaction is, -277.4 kJ
Diamonds are composed of carbon in a tetrahedral lattice. That is option C.
<h3>What is a diamond?</h3>
A diamond of defined as an allotrope or one of the major forms of the element, carbon in nature.
These carbon atoms are arranged within the diamond in a face centered cubic tetrahedral lattice shape.
Therefore, Diamonds are composed of carbon in a tetrahedral lattice.
Learn more about carbon here:
brainly.com/question/19083306
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Answer:
we can do it again and again and again and again and again and again
Answer: Malleability
Explanation: is a physical property of metals that defines their ability to be hammered, pressed, or rolled into thin sheets without breaking. In other words, it is the property of a metal to deform under compression and take on a new shape.