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:
D Cobalt
Explanation:
The volume of the sphere is 40 -25 = 15 cm^3
Density = mass/volume = 133 gm / 15 cm^3 = 8.87 gm/cm^3
which corresponds to Cobalt from the chart
This process is called filtration. This process is a solid-fluid separation by the use of a medium wherein only the fluid (gases or liquids) can go through it. The medium is called the filter while the fluid that passed through the filter is called the filtrate. The solid particles are the large particles which cannot pass through the filter.
C. CO2, carbon dioxide is a covalent compound,it is not formed from its respective ions,it does not donate or receive electrons to form a compound
F. because electronegativity generally increases as you move from left to right across a periodic table, and F is farther right than O
