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:
116.5 g of SO₂ are formed
Explanation:
The reaction is:
S₈(g) + 8O₂(g) → 8SO₂ (g)
Let's identify the moles of sulfur vapor, by the Ideal Gases Law
We convert the 921.4°C to Absolute T° → 921.4°C + 273 = 1194.4 K
5.87 atm . 3.8L = n . 0.082 L.atm/mol.K . 1194.4K
(5.87 atm . 3.8L) / (0.082 L.atm/mol.K . 1194.4K) = n → 0.228 moles of S₈
Ratio is 1:8, 1 mol of sulfur vapor can produce 8 moles of dioxide
Then, 0.228 moles of S₈ must produce (0.228 . 8) /1 = 1.82 moles
We convert the moles to g → 1.82 moles . 64.06 g /1mol = 116.5 g
I think it's calorie
Hope this helps
Answer: A. To change the potential energy of the reactants.
Explanation:
Catalysts make such a breaking and rebuilding happen more efficiently. They do this by lowering the activation energy for the chemical reaction. Activation energy is the amount of energy needed to allow the chemical reaction to occur. The catalyst just changes the path to the new chemical partnership.
The uranium within these items is radioactive and should be treated with care. Uranium's most stable isotope, uranium-238, has a half-life of about 4,468,000,000 years. It decays into thorium-234 through alpha decay or decays through spontaneous fission.
