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.
Fe^2+ makes Mg go from 0 to 2+, Fe^2+ is the oxidizing, Mg makes Fe^2+ go from 2+ to 0, Mg is the reducing.
Fe^2+ is a chemical symbol for ferrous in chemistry. Ferrous refers to iron with oxidation number of +2, denoted iron(II) or Fe2+.
Mg is a chemical symbol for Magnesium in chemistry.
K value of water is 1x 10^-14
T<span>he balanced reaction is as follows;
Ca(OH)</span>₂<span> + 2HCl ---> CaCl</span>₂<span> + 2H</span>₂<span>O
stoichiometry of Ca(OH)</span>₂<span> to HCl is 1:2
number of moles of Ca(OH)</span>₂<span> reacted = 0.120 mol/L x 0.0240 L = 0.00288 mol according to molar ratio of 1:2 number of HCl moles reacted = twice the number of Ca(OH)</span>₂<span> moles reacted
number of HCl moles reacted = 0.00288 mol x 2 = 0.00576 mol
number of HCl moles in 160 mL - 0.00576 mol
therefore number of HCl moles in 1000 mL - 0.00576 mol / 160 mL x 1000 mL = 0.036 mol
molarity of HCl = 0.036 M</span>