Answer:
The ΔHrxn for the above equation = 179 kJ/mol
Explanation:
The reaction bond enthalpies are for the reactant;
3 × N-H = 3 × 390 = 1,170 kJ/mol
2 × O=O = 2 × 502 = 1004 kJ/mol
The reaction bond enthalpies are for the product;
3 × N-O = 3 × 201 = 603 kJ/mol
3 × O-H = 3 × 464 = 1,392 kJ/mol
The ΔHrxn for the above equation is therefore;
ΔHrxn = 1,170 + 1,004 - (603 + 1,392) = 179 kJ/mol
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<h2>
Answer:</h2>
ZINC
<h2>
Explanation:</h2>
<em>To identify the element based on the informartion given, we have to find the molar mass since this mass is unique to each element.</em>
Molar mass = mass ÷ moles
<em>We already know the mass based on the question, as such we now need to find the # of moles.</em>
Since 1 mole contains 6.02214 × 10²³ atoms
then let x moles contain 4.19 × 10²³ atoms <em>(given in the question)</em>
<em> </em><em> </em> ⇒ x = (4.19 × 10²³ atoms × 1 mol) ÷ 6.02214 × 10²³ atoms
x = 0.69577 mol
<em>Now that we have the moles we can substitute it into the molar mass equation and solve for the molar mass.</em>
⇒ molar mass = 45.6 g ÷ 0.69577 mol
⇒ molar mass ≈ 65.54 g/mol
This molar mass is closest to that of ZINC.