Answer:
2:1<em><u> </u></em><em><u> </u></em><em><u>of </u></em><em><u> </u></em><em><u>Tc </u></em><em><u>in </u></em><em><u>the</u></em><em><u> </u></em><em><u>periodic</u></em><em><u> table</u></em>
Answer: 167 g
Explanation:
1) The depression of the freezing point of a solution is a colligative property ruled by this equation:
ΔTf = i × m × Kf
Where:
ΔTf is the decrease of the freezing point of the solvent due to the presence of the solute.
i is the Van't Hoof factor and is equal to the number of ions per each mole of solute. It is only valid for ionic compounds. Here the solute is not ionice, so you take i = 1
Kf is the molal freezing constant and is different for each solvent. For water it is 1.86 m/°C
2) Calculate the molality (m) of the solution
ΔTf = i × m × Kf ⇒ m = ΔTf / ( i × Kf) = 5.00°C / 1.86°C/m = 2.69 m
3) Calculate the number of moles from the molality definition
m = moles of solute / kg of solvent ⇒ moles of solute = m × kg of solvent
moles of solute = 2.69 m × 1.00 kg = 2.69 moles
4) Convert moles to grams using the molar mass
molar mass of C₂H₆O₂ = 62.07 g/mol
mass in grams = number of moles × molar mass = 2.69 moles × 62.07 g/mol = 166.97 g ≈ 167 g
When
Aldehyde is reacted with
Alcohol in the presence of
acid the it gives
Hemiacetal, Hemiacetal on further reaction with acid and alcohol gives
Acetal.
In given problem the aldehyde given is
P<span>
henylacetaldehyde and alcohol is
Methanol. The reaction is done stepwise as shown below,</span>
Henry law:
P = KC
P = solvent vapour pressure
K = Henry constant
C = conc of solute
So, 0.2 = 773 C
so, C = 0.2 / 773 = 2.5 x 10^{-4} molal
