Your best answer for 1 is B.
Answer:
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- <u><em>3.42 moles</em></u>
Explanation:
By the law of conservation of energy, assuming no losses of heat to the surroundings, <em>the amount of heat consumed by the dissolution of the ammonium nitrate is equal to the amount of heat released from the water.</em> This is, the ammonium nitrate absorbs all the heat it needs to break the ions apart and get dissolved from the water in which it is being dissolved.
Thus:
↑ ↑ ↑
heat released number of moles molar heat of solution
from water of NH₄NO₃ for NH₄NO₃
Solve for n and compute:
- n = 88.0kJ / (25.7kJ/mol) = 3.42 moles ← answer
Answer:
Exothermic
q = -8.03 kJ/g
Explanation:
<em>When 2 moles of Na(s) react with H₂O(l) to form NaOH(aq) and H₂(g) according to the following equation, 369 kJ of energy are evolved.</em>
The thermochemical equation is:
2 Na(s) + 2 H₂O(l) → 2 NaOH(aq) + H₂(g) ΔH = -369 kJ
Since the energy is evolved, the reaction is exothermic, which is why the enthalpy of the reaction (ΔH) is negative.
The heat released (q) per gram of Na(s) is (molar mass 22.98 g/mol):
Answer:
four covalent bonds
Explanation:
A carbon atom would form 4 covalent bonds.
For a covalent bond to be formed, an atom would share its valence electrons with another. In this process, each atom would require unpaired electrons for this bond to be formed. The number of available unpaired electrons would represent the number of electrons needed to complete the outer energy level of the atom.
In a carbon atom, we have no lone pair of electrons and 4 unpaired electrons. When these 4 electrons are shared with those of other atoms, they produce a complete octet which perfectly mimics the noble gases.
Christopher columbus........