Answer:
A
Explanation:
Recall that Δ<em>H</em> is the sum of the heats of formation of the products minus the heat of formation of the reactants multiplied by their respective coefficients. That is:
Therefore, from the chemical equation, we have that:
![\displaystyle \begin{aligned} (-317\text{ kJ/mol}) = \left[\Delta H^\circ_f \text{ N$_2$H$_4$} + \Delta H^\circ_f \text{ H$_2$O} \right] -\left[3 \Delta H^\circ_f \text{ H$_2$}+\Delta H^\circ_f \text{ N$_2$O}\right] \end{aligned}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Cbegin%7Baligned%7D%20%28-317%5Ctext%7B%20kJ%2Fmol%7D%29%20%3D%20%5Cleft%5B%5CDelta%20H%5E%5Ccirc_f%20%5Ctext%7B%20N%24_2%24H%24_4%24%7D%20%2B%20%20%5CDelta%20H%5E%5Ccirc_f%20%5Ctext%7B%20H%24_2%24O%7D%20%20%5Cright%5D%20%20%20-%5Cleft%5B3%20%5CDelta%20H%5E%5Ccirc_f%20%5Ctext%7B%20H%24_2%24%7D%2B%5CDelta%20H%5E%5Ccirc_f%20%5Ctext%7B%20N%24_2%24O%7D%5Cright%5D%20%5Cend%7Baligned%7D)
Remember that the heat of formation of pure elements (e.g. H₂) are zero. Substitute in known values and solve for hydrazine:
![\displaystyle \begin{aligned} (-317\text{ kJ/mol}) & = \left[ \Delta H^\circ _f \text{ N$_2$H$_4$} + (-285.8\text{ kJ/mol})\right] -\left[ 3(0) + (82.1\text{ kJ/mol})\right] \\ \\ \Delta H^\circ _f \text{ N$_2$H$_4$} & = (-317 + 285.8 + 82.1)\text{ kJ/mol} \\ \\ & = 50.9\text{ kJ/mol} \end{aligned}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20%5Cbegin%7Baligned%7D%20%28-317%5Ctext%7B%20kJ%2Fmol%7D%29%20%26%20%3D%20%5Cleft%5B%20%5CDelta%20H%5E%5Ccirc%20_f%20%5Ctext%7B%20N%24_2%24H%24_4%24%7D%20%2B%20%28-285.8%5Ctext%7B%20kJ%2Fmol%7D%29%5Cright%5D%20-%5Cleft%5B%203%280%29%20%2B%20%2882.1%5Ctext%7B%20kJ%2Fmol%7D%29%5Cright%5D%20%5C%5C%20%5C%5C%20%5CDelta%20H%5E%5Ccirc%20_f%20%5Ctext%7B%20N%24_2%24H%24_4%24%7D%20%26%20%3D%20%28-317%20%2B%20285.8%20%2B%2082.1%29%5Ctext%7B%20kJ%2Fmol%7D%20%5C%5C%20%5C%5C%20%26%20%3D%2050.9%5Ctext%7B%20kJ%2Fmol%7D%20%5Cend%7Baligned%7D)
In conclusion, our answer is A.
<u>Answer;</u>
-Work
If Jerome is swinging on a rope and transferring energy from gravitational potential energy to kinetic energy, <u>work </u> is being done.
<u>Explanation;</u>
- Work refers to the application of a given force over a distance. Thus, we can say work is the product of force and distance.
- Energy on the other hand is the ability of a body to change, its location, shape, or state of another body.
- According to the work-Energy principle, a change in the kinetic energy, which is the energy possessed by a body in motion, is equivalent to the net work done on the body.
Answer:We decided to pasteurize the documents for safekeeping
Explanation:
Answer:
1) P₄ + 5O₂ → P₄O₁₀ redox reaction
2) P₄O₁₀ + 6H₂O → 4H₃PO₄ acid-base reaction
3) Ca₅(PO₄)₃F + 5H₂SO₄ → 3H₃PO₄ + HF + 5CaSO₄ precipitation reaction
Explanation:
The reactions that take place in the <u>electric furnace method</u> are:
1) P₄ + 5O₂ → P₄O₁₀
This is a redox reaction, because the oxidation state of the reactants is changed.
2) P₄O₁₀ + 6H₂O → 4H₃PO₄
This is an acid-base reaction, because there's an exchange of H⁺ species.
The reaction that takes place in the <u>wet process</u> is:
3) Ca₅(PO₄)₃F + 5H₂SO₄ → 3H₃PO₄ + HF + 5CaSO₄
This is an precipitation reaction, because a precipitate (a solid phase in a liquid phase) is formed.
