Answer:
P' = 41.4 mmHg → Vapor pressure of solution
Explanation:
ΔP = P° . Xm
ΔP = Vapor pressure of pure solvent (P°) - Vapor pressure of solution (P')
Xm = Mole fraction for solute (Moles of solvent /Total moles)
Firstly we determine the mole fraction of solute.
Moles of solute → Mass . 1 mol / molar mass
20.2 g . 1 mol / 342 g = 0.0590 mol
Moles of solvent → Mass . 1mol / molar mass
60.5 g . 1 mol/ 18 g = 3.36 mol
Total moles = 3.36 mol + 0.0590 mol = 3.419 moles
Xm = 0.0590 mol / 3.419 moles → 0.0172
Let's replace the data in the formula
42.2 mmHg - P' = 42.2 mmHg . 0.0172
P' = - (42.2 mmHg . 0.0172 - 42.2 mmHg)
P' = 41.4 mmHg
Answer:
Mass of water = 73.08 g
Explanation:
Given data:
Mass of hydrogen = 35 g
Mass of oxygen = 65 g
Mass of water = ?
Solution:
First of all we will write the balanced chemical equation:
2H₂ + O₂ → 2H₂O
Number of moles of hydrogen = mass/ molar mass
Number of moles of hydrogen = 35 g/ 2 g/mol
Number of moles of hydrogen = 17.5 mol
Number of moles of oxygen = 65 g / 32 g/mol
Number of moles of oxygen = 2.03 moles
Now we compare the moles of water with moles hydrogen and oxygen.
H₂ : H₂O
2 : 2
17.5 : 17.5
O₂ : H₂O
1 : 2
2.03 : 2× 2.03 =4.06 mol
Number of moles of water produced by oxygen are less so oxygen is limitting reactant.
Mass of water:
Mass of water = number of moles × molar mass
Mass of water = 4.06 mol × 18 g/mol
Mass of water = 73.08 g
