The mole ratio of PbO2 to water in
Pb + PbO2 +2 H2SO4 = 2PbSO4 + 2H2O is
1 :2
1 mole of Pb reacted with 1 mole of PbO2 and 2 moles of H2SO4 to form 2 moles of PbSO4 and 2 moles of H2O
therefore the mole ratio of Pbo2 to H2O is 1:2
D iron oxide Fe is a transition metal
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Answer:
Explanation:
The equation is given as:
CH3CHOHC2H4CHO + CH3OH --> CYCLIC ACETAL + H2O
This above equation is carried out in the presence of a strong acid. There are five mechanisms employed and they are:
Step 1:
Initial formation of the hemiacetal which takes several steps
Step 2:
Addition of a proton. The hemicetal is protonated on the hydroxyl group (-OH group)
Step 3:
As seen a bond is broken to give the H2O molecule and a resonance stabilized cation.
The carbonyl group on the cation is enriched with the oxygen-18 got from the H2O molecule as seen in the mechanism.
Step 4:
An attraction occurs between electrophile and nucleophile i.e the stabilised cation and the lone paids of the methanol.
Step 5:
Finally, a proton (+) is removed from the molecule by a lone pair of electron on the methanol.
Attached are the Steps 1 - 5 mechanism below
Answer:
None of the options are correct.
Explanation:
1) when the temperature of the solution is increased the solubility of the gas in the liquid decreases , hence option 1 is incorrect.
2)The heat released by the dissolution of an ionic compound in water is heat of hydration of the compound and is independent of the initial temperature of the solution.
3) The solubility of a liquid in water is not affected significantly by the pressure changes in the system as gases only have a significant cahne in solubility with change in pressure.
Data:
solute: ethylene glicol => not ionization
molar mass of ethylene glicol (from internet) = 62.07 g/mol
solute = 400 g
solvent = water = 4.00 kg
m =?
ΔTf = ?
Kf = 1.86 °C/mol
Formulas:
m: number of moles of solute / kg of solvent
ΔTf = Kf*m
number of moles of solute = mass in grams / molar mass
Solution
number of moles of solute = 400 g / 62.07 g/mol = 6.44 moles
m = 6.44 mol / 4 kg = 1.61 m <-------- molality (answer)
ΔTf = 1.86 °C / m * 1.61 m = 2.99 °C <---- lowering if freezing point (answer)
