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.
A neutral atom of potassium has 19 electrons.
Answer:
one advantage of KLO3 as a primary standard is that it is used to know concentration of a solution.
Explanation:
The reaction provides confirmation that the solution is at a specific concentration. Primary standards are often used to make standard solutions (a solution with a precisely known concentration
Answer : The incorrect option is, The most of the mass of the atom comes from the electron cloud.
Explanation :
There are three basic particles of an atom which are neutrons, protons and electrons.
The nucleus which is present in the center of an atom that contains the neutrons and the protons. The protons are positively charged and neutrons has no charge.
The outer region of an atom contains the electrons and the electrons are negatively charged.
As per given options, the statement which is the most of the mass of the atom comes from the electron cloud is incorrect statement because the most of the mass comes from the nucleus in which protons and neutrons are present.
Answer:
When an atom gains or loses energy, the energy of an electron can change.
An electron in an atom can move from one energy level to another when the atom gains or loses energy.
Explanation:
The possible energies that electrons in an atom
can have are called energy levels.
• An electron cannot exist between energy levels.
https://1.cdn.edl.io/tTlW7xRtvD62xSe7RcZlJr7kSR7XsL93akcgJkbGJBNNcpwY.pdf
*this link can also help* brainly ist plz
