Answer: ![\Delta H^{0} = -879.15 kJ/mol](https://tex.z-dn.net/?f=%5CDelta%20H%5E%7B0%7D%20%3D%20-879.15%20kJ%2Fmol)
Explanation: <u>Heats</u> <u>of</u> <u>formation</u> is the amount of heat necessary to create 1 mol of a compound from its molecular constituents. The basic conditions the substance is formed is at standard conditions: 1 atm and 25°C. Each compound has its own heat of formation per mol of compound (kJ/mol), but to an element is assigned a value of zero.
<u>Standard</u> <u>Enthalpy</u> <u>Change</u> is defined as the heat absorbed or released when a reaction takes place. It can be positive or negative, which means reaction is endothermic or exothermic, respectively.
Enthalpy change is calculated as the difference between the sum of heat formation of products and the sum of heat formation of the reactants:
![\Delta H^{0}=\Sigma H^{0}_{f}_{(products)}-\Sigma H^{0}_{f}_{(reactants)}](https://tex.z-dn.net/?f=%5CDelta%20H%5E%7B0%7D%3D%5CSigma%20H%5E%7B0%7D_%7Bf%7D_%7B%28products%29%7D-%5CSigma%20H%5E%7B0%7D_%7Bf%7D_%7B%28reactants%29%7D)
For the reaction
2NH₃ + 3N₂O → 4N₂ + 3H₂O
2(-46.2) + 3(82.05) 4(0) + 3(-241.8)
![\Delta H^{0}=3(-241.8)-[ 2(-46.2)+3(82.05)]](https://tex.z-dn.net/?f=%5CDelta%20H%5E%7B0%7D%3D3%28-241.8%29-%5B%202%28-46.2%29%2B3%2882.05%29%5D)
![\Delta H^{0}=-725.4-153.75](https://tex.z-dn.net/?f=%5CDelta%20H%5E%7B0%7D%3D-725.4-153.75)
![\Delta H^{0}=-879.15](https://tex.z-dn.net/?f=%5CDelta%20H%5E%7B0%7D%3D-879.15)
<u>The standard enthalpy change for the reaction is </u>
<u> kJ</u>
Answer:
Regularly test the water in residents' homes.
Explanation:
The only way to know if tap water contains lead is to do tests to determine the levels of that metal in the water. Therefore, the state is under an obligation to constantly conduct such tests in the resident´s homes and thus determine whether the water supplied is fit for human consumption.
The state after the tests must guarantee the population the treatment of the water to reduce the levels of lead. The main pipes that contain lead pipes must be changed, as well as those parts of the service connections made of lead.
I believe Neon is closest to Magnesium on the Periodic Table of elements.
Sorry if I'm wrong, hope I could help though! :)
I believe the most massive element that is naturally occurring on Earth is uranium (U), which has a nucleus of 92 protons