The full question asks to decide whether the gas was a specific gas. That part is missing in your question. You need to decide whether the gas in the flask is pure helium.
To decide it you can find the molar mass of the gas in the flask, using the ideal gas equation pV = nRT, and then compare with the molar mass of the He.
From pV = nRT you can find n, after that using the mass of gass in the flask you use MM = mass/moles.
1) From pV = nRT, n = pV / RT
Data:
V = 118 ml = 0.118 liter
R = 0.082 atm*liter/mol*K
p = 768 torr * 1 atm / 760 torr = 1.0105 atm
T = 35 + 273.15 = 308.15 K
n = 1.015 atm * 0.118 liter / [ 0.082 atm*liter/K*mol * 308.15K] =0.00472 mol
mass of gas = mass of the fask with the gas - mass of the flasl evacuated = 97.171 g - 97.129 g = 0.042
=> MM = mass/n = 0.042 / 0.00472 = 8.90 g/mol
Now from a periodic table or a table you get that the molar mass of He is 4g/mol
So the numbers say that this gas is not pure helium , because its molar mass is more than double of the molar mass of helium gas.
Answer :
<em><u>Explanation For The Three States OF Matter On the Basis OF Characteristics Of Particles / Molecules OF Matter.</u></em>
<h3><em><u>S</u></em><em><u>o</u></em><em><u>l</u></em><em><u>i</u></em><em><u>d</u></em><em><u>:</u></em><em><u> </u></em></h3>
<em><u>In solids the molecules are closely packed . There is a strong force of attraction between the molecules and the space between them is very small (almost negligible). The molecules are , therefore, not free to move . They merely vibrate their mean positions . This makes solids hard and difficult to compress , giving them a fixed shape and size.</u></em>
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<em><u>In the case of liquids , the molecules are not closely packed. They do not attract each other as strongly as the molecules of solids. Thus, the intermolecular spaces are larger and the molecules are able to move about more freely . This makes liquid flow and take the shape of the container into which it is poured. Thus, liquids have a fixed volume but no def</u></em><em><u>i</u></em><em><u>nite shape of their own .</u></em>
<h3><em><u>G</u></em><em><u>a</u></em><em><u>s</u></em><em><u> </u></em><em><u>:</u></em><em><u> </u></em></h3>
<em><u>In the case of gases, the molecules hardly attract each other. They lie far a part from each other and the intermolecular spaces are, therefore, very large. . The intermolecular force of attraction is so weak that the molecules have great freedom of movement . As a result , gases have neither a fixed shapenor a fixed volume . They completely full up spacw available to them. They can be easily compressed as well, thus decreasing the gaps between their molecules .</u></em>
Explanation :
<h3><em><u>H</u></em><em><u>o</u></em><em><u>p</u></em><em><u>e</u></em><em><u> </u></em><em><u>i</u></em><em><u>t</u></em><em><u> </u></em><em><u>w</u></em><em><u>o</u></em><em><u>r</u></em><em><u>k</u></em><em><u>s</u></em><em><u> </u></em><em><u>o</u></em><em><u>u</u></em><em><u>t</u></em><em><u> </u></em><em><u>!</u></em></h3>
Most fertilizers are rich in nitrogen and phosphorous because they have to replenish nitrogen and phosphorous in the soil, which are essential for plant growth. If they didn't have this, the soil would have to wait fro another cycle and this would hinder plant growth. The correct answer is C.