The value of ΔH° for the reaction below is -126 kJ. The amount of heat that is released by the reaction of 40.0 g of Na2O2 with water is kJ. 2Na2O2 (s) + 2H2O (l) → 4NaOH (s) + O2 (g)

-32.3 kJ

Explanation:

Step 1: Write the balanced thermochemical equation

2 Na₂O₂(s) + 2 H₂O(l) ⇒ 4 NaOH(s) + O₂(g)   ΔH° = -126 kJ

Step 2: Calculate the moles corresponding to 40.0 g of Na₂O₂

The molar mass of Na₂O₂ is 77.98 g/mol.

40.0 g × 1 mol/77.98 g = 0.513 mol

Step 3: Calculate the amount of heat released upon the reaction of 0.513 moles of Na₂O₂

According to the thermochemical equation, 126 kJ of heat are released every 2 moles of Na₂O₂.

0.513 mol Na₂O₂ × (-126 kJ/2 mol Na₂O₂) = -32.3 kJ

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.