Answer:
(a) Benzene = 0.26; toluene = 0.74
(b) Benzene = 0.55
Explanation:
1. Calculate the composition of the solution
For convenience, let’s call benzene Component 1 and toluene Component 2.
According to Raoult’s Law,

where
p₁ and p₂ are the vapour pressures of the components above the solution
χ₁ and χ₂ are the mole fractions of the components
p₁° and p₂° are the vapour pressures of the pure components.
Note that
χ₁ + χ₂ = 1
So,

χ₁ = 0.26 and χ₂ = 0.74
2. Calculate the mole fraction of benzene in the vapour
In the liquid,
p₁ = χ₁p₁° = 0.26 × 75 mm = 20 mm
∴ In the vapour

Note that the vapour composition diagram below has toluene along the horizontal axis. The purple line is the vapour pressure curve for the vapour. Since χ₂ has dropped to 0.45, χ₁ has increased to 0.55.
Answer:
Mass of KNO3 in the original mix is 146.954 g
Explanation:
mass of
in original 254.5 mixture.
moles of 
moles of
= 0.2926 mol of BaSO4
Therefore,
0.2926 mol of BaCl2,
mass of 
= 60.92 g
the AgCl moles 

= 1.3891 mol of AgCl
note that, the Cl- derive from both,
so
mole of Cl- f NaCl
mol of Cl-
mol of NaCl = 0.8039 moles

then
KNO3 mass = 254.5 - 60.92-46.626 = 146.954 g of KNO_3
Mass of KNO3 in the original mix is 146.954 g
well its evaporation cuz it the suns heat heated the ice to the point where it turned to a gas, it could be conduction cuz the heat of the sunshine conducted the ice and turned it to a gas but that would be evaporation too so its not onduction, its not a chemical change cuz theres no new molecule the substance is itself, and its not a sudden change obviously
so the answer is A. evaporation~~~
Yes indeed yes indeed yes indeed
Answer:
41.63g
Explanation:
Given parameters:
Volume of CaCl₂ = 500mL = 0.5L
Concentration = 0.75mol/L
Unknown:
Mass of the solute needed = ?
Solution:
The mass of the solute can be derived using the expression below;
Mass = number of moles x molar mass
But,
Number of moles = Concentration x Volume
So;
Mass = Concentration x Volume x molar mas
Molar mass of CaCl₂ = 40 + 2(35.5) = 111g/mol
Mass = 0.75 x 0.5 x 111 = 41.63g