Answer:
At the burner temp. and pressure, 18.85 litres of air is needed to completely combust each gram of propane
Explanation:
The combustion stoichiometry is as follows:
C₃H₈ + 5O₂ = 4 H₂O + 3CO₂ The molecular weights (g/mol) are:
MW 44 5x32 4x18 3x44
So each gram of propane is 1/44 = 0.02272 mol propane
and will need 5 x 0.02272 = 0.1136 mol oxygen
At 0.21 mol fraction oxygen in air, 0.1136 / 0.21 = 0.54 mol air is needed to burn the propane.
At the low pressure in the burner we can use the Ideal Gas Law
PV=nRT, or V = nRT/P
P = 1.1 x 101325 Pa = 111457 Pa
T = 195°C + 273 = 468 K
R = 8.314
and we calculated n = number of moles air = 0.54 mol
So V m³ = 0.54 x 8.314 x 468 / 111457 = 0.0188 m³ = 18.85 litres air.
Answer:
The answer is Facilitated Diffusion
Explanation:
Osmosis is most similar to facilitated diffusion.
Osmosis can be defined as : Osmosis is the movement of water molecules across a semi-permeable membrane, down a concentration gradient from a low concentrated solution into a more concentrated solution.
Facilitated diffusion is defined as: Facilitated diffusion is the flow of molecules requiring the aid of a protein, across a membrane, down a concentration gradient from a low concentrated solution into a more concentrated one.
Answer:
Mass = 182.4 g
Explanation:
Given data:
Number of moles of Al₂O₃ = 3.80 mol
Mass of oxygen required = ?
Solution:
Chemical equation:
4Al + 3O₂ → 2Al₂O₃
Now we will compare the moles of aluminum oxide and oxygen.
Al₂O₃ : O₂
2 : 3
3.80 : 3/2×3.80 = 5.7
Mass of oxygen:
Mass = number of moles × molar mass
Mass = 5.7 mol × 32 g/mol
Mass = 182.4 g
Answer:
D
Explanation:
( I hope that this helps )
Answer:
By adding the solute in to solution boiling point is increased while freezing point is decreased.
Explanation:
When solute in added into the solvent the boiling point of solvent increases for example,
Water is boiled at 100 °C, when sodium chloride is added its boiling point increased. Ions of salt interact with solvent and prevent the water molecules to escape from the surface and form gas molecules. In order to make it boiled solution must be heated above 100 °C.
But there is different case with freezing point. Freezing point is the state in which substance converted into the solid. At given temperature when solute is added into the solvent it prevent the formation of solid. It required time to decrease the temperature first and as the temperature is decreases solid is formed.
