Answer:
28 as compare to ul formula
Answer:
Air is less dense on a mountaintop than at sea level.
Air pressure is lower at low altitudes.
As you climb a mountain, air pressure increases.
More force pushes on the air at the bottom of an air column.
As you descend a mountain, air molecules are closer together.
Explanation:
Answer:
ΔrxnH = -580.5 kJ
Explanation:
To solve this question we are going to help ourselves with Hess´s law.
Basically the strategy here is to work in an algebraic way with the three first reactions so as to reprduce the desired equation when we add them together, paying particular attention to place the reactants and products in the order that they are in the desired equation.
Notice that in the 3rd reaction we have 2 mol Na₂O (s) which is a reactant but with a coefficient of one, so we will multiply this equation by 1/2-
The 2nd equation has Na₂SO₄ as a reactant and it is a product in our required equation, therefore we will reverse the 2nd . Note the coefficient is 1 so we do not need to multiply.
This leads to the first equation and since we need to cancel 2 NaOH, we will nedd to multiply by 2 the first one.
Taking 1/2 eq 3 + (-) eq 2 + 2 eq 1 should do it.
Na₂O (s) + H₂ (g) ⇒ 2 Na (s) + H₂O(l) ΔrxnHº = 259 / 2 kJ 1/2 eq3
+ 2NaOH(s) + SO₃(g) ⇒ Na₂SO₄ (s) + H₂O (l) ΔrxnHº = -418 kJ - eq 2
+ 2Na (s) + 2 H₂O (l) ⇒ 2 NaOH (s) + H₂ (g) ΔrxnHº = -146 x 2 2 eq 1
<u> </u>
Na₂O (s) + SO₃ (g) ⇒ Na₂SO₄ (s) ΔrxnHº = 259/2 + (-418) + (-146) x 2 kJ
ΔrxnH = -580.5 kJ
So, we have:
- molecular weight
- shape
- temperature
- kinetic energy
- mass
- density
Let's rule out the different options.
- molecular weight: Say you have a molecule of H2O. H2O can be a solid, liquid, or gas, but its molecular weight never changes throughout (It's still the same molecule, no matter what phase it is in). We can rule this out.
- shape: Let's pretend we have three identical closed containers, and we fill each one halfway with water, blocks of ice cubes, and water vapor. In the container with water, you will see that the water takes the shape of the container, but doesn't fill the entire container up. The ice cubes will stay ice cubes, assuming they don't melt, so they don't take the shape of the container. The vapor will fill up the entire container. Since all three are different, I would say yes, this could be a distinguishable feature.
- temperature: In general, I would say no, because every element/molecule has different boiling points and different vaporization points. So if you have a liquid at 5°C, you could also have a different element in solid form at 5°C. But if you're comparing a single type of molecule, it would have a boiling point and a vaporization point, so you <em>would</em> be able to tell between them.
- kinetic energy: Kinetic energy refers to how much movement there is in respect to each molecule. In solids, the molecules are packed tightly together and can't move very much, so they have lower kinetic energy. In liquids, they are less packed, but still restricted. And in gases, they can fly freely, so they will have much more kinetic energy than liquids or solids. This one's a yes.
- mass: No matter what form, there are still the same amount of molecules, and each molecule has the same mass as before. It won't change.
- density: Since the molecules are more spread out in gases, it will be less dense. Liquids will be more dense, and solids will have the greatest density. So, yes.
Conclusion: shape, kinetic energy, density, (and temperature if it's talking about a single type of molecule)
Answer:
Chemical energy
Explanation:
Energy in carbohydrates is stored as chemical energy which is released when the carbohydrate is broken down by the body to give glucose and ATP. Animals eat carbohydrates as energy molecules from which they derive energy from the stored chemical energy.
