Answer:
Which are bundles of cells in the lungs that take in oxygen? Alveoli.
Explanation:
Answer option A is correct. Hope you have a great day.
<span>N2(g) + 2 O2(g) → 2 NO2(g)
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(1) N2(g) + O2(g) → 2 NO(g) Δh = +180.7 kJ
(2) 2 NO(g) + O2(g) → 2 NO2(g) Δh = −113.1 kJ
(3) 2 N2O(g) → 2 N2(g) + O2(g) Δh = −163.2 kJ
You want to rearrange the given reactions to match the reaction with the unknown enthalpy. Looking at what we're given, reaction (2) already has 2NO2 on the product side just like our unknown, so let's start there - it can stay as is.
However, it has 2NO on the reactant side - that's not in our unknown reaction, so we need to get rid of it somehow. There's 2NO in reaction (1), and it's on the product side, so it will cancel the 2NO on the reactants side of reaction (2). This means reaction (1) can stay as it is as well.
If you add these two reactions together, you'll get:
N2(g) + O2(g) + 2 NO(g) + O2(g)→ 2 NO(g) + 2 NO2(g)
N2(g) + 2O2(g) + 2 NO(g) → 2 NO(g) + 2 NO2(g)
N2(g) + 2O2(g) → 2 NO2(g)
The 2 NO cancels out and the individual O2's add together to get 2O2. This gives us the unknown reaction so we actually don't need to use reaction (3) at all to answer this question. In fact, it makes things more difficult because it contains N2O, which cannot be cancelled in any way with the reactions we're given.
To find the enthalpy of the unknown reaction, add the enthalpies of the reactions that work. Since we didn't have to modify either of the the first 2 reactions, you can add their original enthalpies as given:
+180.7 kJ + (−113.1 kJ) = +67.6 kJ
Answer:
The ion will repel the substance because it has lost two electrons.
Explanation:
An ion is a charged specie. We can see from the question that the ion has twelve positive and ten negative particles.
If there are more positive particles than negative particles, then the ion is positively charged.
If the ion is positively charged, it will repel another positively charged particle because like charges repel while opposite charges attract.
"Aristotle," thought that everything was made from "earth", "air", "fire" and "water".
Option: D
Explanation:
"Aristotle" was against to "Atomic theory" so he believed that all the things were made from earth, air, fire and water called "four classical elements". These are "four classical elements" responsible for creating all the things in "terrestrial spheres". "Aristotle" started believing that all many of the little substances were "made up" of these "four classical elements" earth, air, fire and water. But "Aristotle" views on "elements" went wrong. "Aristotle" also grasped that "heavens" are created by using "weightless" and "unchangeable" the "fifth element" called "Aether".
Answer:
Maybe try to memorize it by the valence electrons. You can do this!!