Answer:
Mass of Ar / Total mass = Mass fraction of Ar
Explanation:
In a mixture, you have three gases:
H₂ + He + Ar
To determinate the mass fraction or argon, you should sum all the mases:
Mass of H₂ + Mass of He + Mass of Ar = Total mass
Afterwards, divide Mass of Ar / Total mass, to find out the mass fraction
Mass of Ar / Total mass = Mass fraction of Ar
You can also x100, to get the mass fraction by %
It says cut it in half so the density would become 4g/mL and the Volume would become 5mL
Answer:
30.12 g/m is the molar mass of the compound
Explanation:
Freezing point depression to solve this. The formula for the colligative property is:
ΔT = Kf . m
ΔT = T° freezing pure solvent - T° freezing solution
Kf = Cryoscopic constant
m = molality (mol/kg)
T° freezing pure benzene: 5.5°C
(5.5°C - 1.02°C) = 5.12 °C/m . m
4.48°C = 5.12 °C/m . m
4.48°C / 5.12 °C/m = m → 0.875 mol/kg
Mol = mass / molar mas
Molality = mol /kg
Let's find out the molar mass, with this equation:
(6.59 g / Molar mass) / 0.250 kg = 0.875 mol/kg
6.59 g / molar mass = 0.875 mol/kg . 0.250 kg
6.59 g / molar mass = 0.21875 mol
6.59 g / 0.21875 mol = molar mass → 30.12 g/m
Answer:
mH₂O = 6.4116 g
Explanation:
Let's write the given reaction:
2H₂ + O₂ -------> 2H₂O
The problem states that 5.7 g of oxygen reacts with excess hydrogen, hence, the limiting reagent is the oxygen. With this mass of oxygen, we can determine the moles, and then, the moles of water with the mole ratio:
moles = mass / atomic weight AW of O₂ = 16 g/mol
Replacing we have:
moles O₂ = 5.70 / (16 * 2)
moles O₂ = 0.1781 moles
According to the balanced reaction, 1 mole of Oxygen produces 2 moles of water, so we have a mole ratio 1:2, therefore the moles of water would be twice the moles of oxygen:
moles H₂O = 0.1781 * 2 = 0.3562 moles
Finally the mass of water can be calculated solving for the mass from the expression of moles, and using molecular mass of water:
m = moles * MM MM H₂O = 18 g/mol
m = 0.3562 * 18
<h2>
mH₂O = 6.4116 g</h2>
Hope this helps
Photons may be generated by the transition of an electron from one energy level in an atom or molecule to a lower energy level. Photons may be absorbed as they cause an electron to be raised from a lower energy level to a higher energy level (in an atom or molecule).
The photon itself does not undergo a transition of energy: it either exists (with an energy defined by its wavelength), or it doesn't exist (it was destroyed!). You could say that the emitting or absorbing atom/molecule/etc. undergoes a change, or transition, in energy. But "transition" is usually used as a name for the process of jumping in energy.
Hope it help
