Aldehydes and ketones react reversibly with two equivalents of alcohol in the presence of an acid catalyst to give acetals. Alco
hols are poor nucleophiles, and so protonation of the carbonyl oxygen is used to make the carbonyl carbon a stronger electrophile. Addition of the first equivalent of alcohol gives a hemiacetal, a hydroxyether. Addition of the second equivalent of alcohol is accompanied by loss of water to yield the product acetal. Draw curved arrows to show the movement of electrons in this step of the mechanism.
1 answer:
Answer:
Aldehyde and ketone both react with alcohols (2 equivalent) in the presence of acid catalyst to give acetals.
Explanation:
Alcohols are poor nucleophiles and so protonation of the carbonyl oxygen used to make the carbonyl carbon a stronger electrophile. Addition of the first equivalent of alcohols gives a hemiacetal,
Addition of the second equivalent of alcohol is accompanied by loss of one molecule water to yield the produce acetal.
You might be interested in
Answer:
Hydrogen: -141 kJ/g
Methane: -55kJ/g
The energy released per gram of hydrogen in its combustion is higher than the energy released per gram of methane in its combustion.
Explanation:
According to the law of conservation of the energy, the sum of the heat released by the combustion and the heat absorbed by the bomb calorimeter is zero.
Qc + Qb = 0
Qc = -Qb [1]
We can calculate the heat absorbed by the bomb calorimeter using the following expression.
Q = C . ΔT
where,
C is the heat capacity
ΔT is the change in the temperature
<h3>Hydrogen</h3>Qc = -Qb = -C . ΔT = -(11.3 kJ/°C) . (14.3°C) = -162 kJ
The heat released per gram of hydrogen is:
Qc = -Qb = -C . ΔT = -(11.3 kJ/°C) . (7.3°C) = -82 kJ
The heat released per gram of methane is:
Answer:
Explanation:
Beta decay conserves the lepton number. In decay, the atomic number of the element increases which is accompanied by the release of an electron antineutrino,
.
For example:-
The decay of silicon-32 is shown below as:-
Answer: The temperature of the gas reduced to 400K.
Explanation:
Stated that ; The pressure remains the same, that is initial and final pressure equals 1atm.
Applying Charles Law
Initial volume V1 = 1
Final volume V2 = 1/2 (halved)
Initial temperature T1 =800K
Final temperature T2 = ?
(1/800) = (1/2)/T2
T2 = 800/2
T= 400K
Therefore, when the volume is halved, the temperature reduced also to half ( 400K)