5.58 X 
Litres is the volume, in liters, occupied by 0.015 molecules of oxygen at STP.
Explanation:
Data given:
molecules of oxygen = 0.015
number of moles of oxygen =?
temperature at STP = 273 K
Pressure at STP = 1 atm
volume = ?
R (gas constant) = 0.08201 L atm/mole K
to convert molecules to moles,
number of moles = 
number of moles = 2.49 x 
Applying the ideal gas law since the oxygen is at STP,
PV = nRT
rearranging the equation:
V = 
putting the values in the rearranged equation:
V = 
V = 5.58 X Litres.
3/5 times 5/3x = 8*3/5. X=24/5 simplified would be x= 4.8 L.
Answer:
It is in the state of "thermal arrest"
Explanation:
The temperature stays constant during the phase change process . This is because the matter has more internal energy and heat has to be taken away for the solidification process to begin. The energy that is required for a phase change is know as latent heat (which is the energy released or absorbed by a body during a thermodynamic process).
A gaseous product is formed
Answer:
2 moles
Explanation:
Let us first start by calculating the molecular mass of Al₂O₃.
The mass of a mole of any compound is called it's molar mass. 1 molar mass 6.02 X 10²³, or Avogadro's number, of compound entities.
Say, 1 mole of Al₂O₃ has 6.02 X 10²³ of Al₂O₃ molecules/atoms. It also has 2*6.02 X 10²³ number of Al atoms and 3*6.02 X 10²³ number of O atoms.
Molecular mass of Al : 26.981539 u
Molecular mass of O: 15.999 u
Therefore, molecular mass of Al₂O₃ is:
= 
u
= 101.960078 u
This can be approximated to 102 u.
1mole weighs 102 u
So, 2moles will weigh 2*102 = 204 u
