According to Raoult's law the relative lowering of vapour pressure of a solution made by dissolving non volatile solute is equal to the mole fraction of the non volatile solute dissolved.
the relative lowering of vapour pressure is the ratio of lowering of vapour pressure and vapour pressure of pure solvent
Where
xB = mole fraction of solute=?
p = 22.8 torr
mole fraction is ratio of moles of solute and total moles of solute and solvent
moles of solvent = mass / molar mass = 500 /18 = 27.78 moles
putting the values
mass of glucose = moles X molar mass = 1.218 X 180 = 219.24 grams
Answer:
The correct answer to you your question is Potassium
Explanation:
Potassium is the most reactive
It oxidized cu since it gains electons.
1. Endothermic reaction
2. Exothermic reaction
3. Exothermic reaction
<u>Explanation:</u>
1. Evaporation of alcohol from the skin, here the heat is absorbed by the alcohol so that it gets evaporated from the skin and it is an endothermic process. As the reaction says that, the energy is added to the system, so it is endothermic.
C₃H₈O + 5.2 kJ → C₃H₈O(g)
2. Burning of propane in a gas grill:
C₃H₈ + 5O₂ → 3CO₂ + 4H₂O + 1652 kJ.
Here energy is released or given out which is termed as exothermic reaction.
3. Oxidation of iron to form rust:
4 Fe + 3O₂ → 2 Fe₂O₃ + 2221 kJ.
Here also energy is released along with the products, so it is termed as exothermic reaction.
Whenever energy is absorbed, the reaction is endothermic in contrast if the energy is released then the reaction is exothermic.
