Answer: A: Explaining natural events using facts and data AND B:Developing theories using many lines of evidence
Explanation: trust me.
#6).
Every 1,000 mL makes 1 L
How many 1,000mL are there in 2,800 mL ?
That's division.
(2,800 mL) / (1,000 mL) = <em>2.8 L</em>
#7).
The 'perimeter' means the 'distance all the way around'.
You have to know that both sides of a rectangle are the same length,
and also the top and bottom are the same length.
So the perimeter of this rectangle is
(2 yd) + (4.5 yd) + (2.yd) + (4.5 yd) = 13 yd .
Oops. The problem wants to know the perimeter in feet.
So you have to know that each yard is the same as 3 feet.
In order to find the number of feet in 13 yards, you have to
take 3 feet 13 <em><u>times</u></em> .
(3 feet) times (13) = <em>39 feet .</em>
#8).
For this one, you have to know that every 36 inches makes 1 yard.
How many 36 inches are there in 48 inches ?
That's division.
(48 inches) / (36inches) = <em>1 and 1/2 yards</em> .
#9).
For this problem, you have to know how to handle a mixed number,
and you also have to know that there are 16 ounces in 1 pound.
Add up the fruit:
(3-1/2 pounds) + (4 pounds) + 2 pounds) = <em><u>9-1/2 pounds</u></em>
Now, remember that each pound is the same as 16 ounces. So if you
want to find the number of ounces in 9-1/2 pounds, you have to take
16 ounces 9-1/2 times .
(16 ounces) times (9-1/2) = <em>152 ounces</em>.
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#10).
This one is just adding up some numbers. But after you finish doing that, you have to know that 1,000 meters is called '1 kilometer' .
Add up the distances that Omar ran:
(1,000 meters) + (1,625 meters) + (1,500 meters) = <em><u>4,125 meters</u></em>
The problem wants to know how many kilometers this is, so you have to figure out how many '1,000 meters' fit into 4,125 meters.
That's division.
(4,125 meters) / (1,000 meters) = <em>4.125 kilometers</em>
The question is incomplete. There's missing the image, which is shown below.
Answer:
Volume of O₂ = 6 L, volume of mixture: 18 L, volume of H₂O = 12 L, molecule volume of H₂O = 0.667 molecule/L
Explanation:
The reaction between hydrogen gas and oxygen gas to form water is:
2H₂(g) + O₂(g) → 2H₂O(g)
So, for 1 mol of O₂ is necessary 2 moles of H₂ form 2 moles of H₂O. As the images below there's 8 molecules of H₂, 4 molecules of O₂, 12 molecules in the mixture, and 8 molecules of H₂O. Thus, there are stoichiometric values.
All the images are at the same temperature and pressure, so, by the ideal gas law:
PV= nRT, where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature.
The number of moles and molecules are related, so let's substitute it in the equation. For the H₂:
P*12 = 8*RT
RT/P = 12/8 = 1.5
Thus, for O₂:
PV= nRT
V = n*(RT/P)
V = 4*1.5 = 6 L
For the mixture:
V = 12*1.5 = 18 L
For H₂O:
V = 8*1.5 = 12 L
The molecule volume is the number of molecules divided by the volume they occupy, thus for water: 8/12 = 0.667 molecules/L
Answer:
![H_{comb}=-4406kJ/mol](https://tex.z-dn.net/?f=H_%7Bcomb%7D%3D-4406kJ%2Fmol)
Explanation:
Hello,
In this case, the enthalpy of combustion is understood as the energy released when one mole of fuel, in this case octene, is burned in the presence of oxygen and is computed with the enthalpies of formation of the fuel, carbon dioxide and water as shown below (oxygen is circumvented as it is a pure element):
![H_{comb}=8*\Delta _fH_{CO_2}+5\Delta _fH_{H_2O}-\Delta _fH_{C_8H_{10}}](https://tex.z-dn.net/?f=H_%7Bcomb%7D%3D8%2A%5CDelta%20_fH_%7BCO_2%7D%2B5%5CDelta%20_fH_%7BH_2O%7D-%5CDelta%20_fH_%7BC_8H_%7B10%7D%7D)
Thus, since we already know the enthalpy of combustion of the fuel, for carbon and water we have -393.5 and -241.8 kJ/mol respectively, thereby, the enthalpy of combustion turns out:
![H_{comb}=8*(-393.5kJ/mol)+5(-241.8kJ/mol)-49.0kJ/mol\\\\H_{comb}=-4406kJ/mol](https://tex.z-dn.net/?f=H_%7Bcomb%7D%3D8%2A%28-393.5kJ%2Fmol%29%2B5%28-241.8kJ%2Fmol%29-49.0kJ%2Fmol%5C%5C%5C%5CH_%7Bcomb%7D%3D-4406kJ%2Fmol)
Best regards.