Chemistry-
General
Easy
Question
In the Hofmann rearrangement an unsubstituted amide is treated with sodium hydroxide and bromine to give a primary amine that has one carbon lesser than starting amide.
General reaction :
Mechanism :
If the migrating group is chiral then its configuration is retained. Electron releasing effects in the migrating group increases reactivity of Hofmann rearrangement.
-
-
-
- B & C both are correct
The correct answer is:
Hoffmann rearrangement is 100% intramolecular. one amide will give only one amine with Br2/OHQ
Related Questions to study
chemistry-
In the Hofmann rearrangement an unsubstituted amide is treated with sodium hydroxide and bromine to give a primary amine that has one carbon lesser than starting amide.
General reaction :
Mechanism :
If the migrating group is chiral then its configuration is retained. Electron releasing effects in the migrating group increases reactivity of Hofmann rearrangement.
Arrange the following amides according to their relative reactivity when reacted with Br2 in excess of strong base
I)
II)
III)
IV)
In the Hofmann rearrangement an unsubstituted amide is treated with sodium hydroxide and bromine to give a primary amine that has one carbon lesser than starting amide.
General reaction :
Mechanism :
If the migrating group is chiral then its configuration is retained. Electron releasing effects in the migrating group increases reactivity of Hofmann rearrangement.
Arrange the following amides according to their relative reactivity when reacted with Br2 in excess of strong base
I)
II)
III)
IV)
chemistry-General
physics-
The tube shown is of uniform cross–section. Liquid flows through it at a constant speed in the direction shown by the arrows. The liquid exerts on the tube
The tube shown is of uniform cross–section. Liquid flows through it at a constant speed in the direction shown by the arrows. The liquid exerts on the tube
physics-General
physics-
A bent arc shaped sealed glass tube filled with water is accelerated horizontally with acceleration a. A small air bubble inside it is found to be stuck at 1 cm from vertical axis. Neglect surface tension. What is the acceleration of the tube.
A bent arc shaped sealed glass tube filled with water is accelerated horizontally with acceleration a. A small air bubble inside it is found to be stuck at 1 cm from vertical axis. Neglect surface tension. What is the acceleration of the tube.
physics-General
physics-
A pan balance has a container of water with an overflow spout on the right-hand pan as shown. It is full of water right up to the overflow spout. A container on the left-hand pan is positioned to catch any water that overflows. The entire apparatus is adjusted so that it’s balanced. A brass weight on the end of a string is then lowered into the water, but not allowed to rest on the bottom of the container. What happens next?
A pan balance has a container of water with an overflow spout on the right-hand pan as shown. It is full of water right up to the overflow spout. A container on the left-hand pan is positioned to catch any water that overflows. The entire apparatus is adjusted so that it’s balanced. A brass weight on the end of a string is then lowered into the water, but not allowed to rest on the bottom of the container. What happens next?
physics-General
physics-
A cylindrical container of length L is full to the brim with a liquid which has mass density r. It is placed on a weigh-scale; the scale reading is W. A light ball which would float on the liquid if allowed to do so, of volume V and mass m is pushed gently down and held beneath the surface of the liquid with a rigid rod of negligible volume as shown on the left.
What is the reading of the scale when the ball is fully immersed?
A cylindrical container of length L is full to the brim with a liquid which has mass density r. It is placed on a weigh-scale; the scale reading is W. A light ball which would float on the liquid if allowed to do so, of volume V and mass m is pushed gently down and held beneath the surface of the liquid with a rigid rod of negligible volume as shown on the left.
What is the reading of the scale when the ball is fully immersed?
physics-General
physics-
A cylindrical container of length L is full to the brim with a liquid which has mass density r. It is placed on a weigh-scale; the scale reading is W. A light ball which would float on the liquid if allowed to do so, of volume V and mass m is pushed gently down and held beneath the surface of the liquid with a rigid rod of negligible volume as shown on the left.
What is the mass M of liquid which overflowed while the ball was being pushed into the liquid?
A cylindrical container of length L is full to the brim with a liquid which has mass density r. It is placed on a weigh-scale; the scale reading is W. A light ball which would float on the liquid if allowed to do so, of volume V and mass m is pushed gently down and held beneath the surface of the liquid with a rigid rod of negligible volume as shown on the left.
What is the mass M of liquid which overflowed while the ball was being pushed into the liquid?
physics-General
physics-
A cubical sealed vessel with edge L is placed on a cart, which is moving horizontally with an acceleration ‘a’ as shown in figure. The cube is filled with a ideal fluid having density r. The gauge pressure at the centre of the cubical vessel is
A cubical sealed vessel with edge L is placed on a cart, which is moving horizontally with an acceleration ‘a’ as shown in figure. The cube is filled with a ideal fluid having density r. The gauge pressure at the centre of the cubical vessel is
physics-General
physics-
The figure below shows four situations in which a gray liquid and a black liquid (which we known nothing about) are in a U tube.
In which of the following situation(s) of static equilibrium must the density of the gray liquid be greater than the density of the black liquid? (circle all appropriate cases)
The figure below shows four situations in which a gray liquid and a black liquid (which we known nothing about) are in a U tube.
In which of the following situation(s) of static equilibrium must the density of the gray liquid be greater than the density of the black liquid? (circle all appropriate cases)
physics-General
physics-
The figure below shows four situations in which a gray liquid and a black liquid (which we known nothing about) are in a U tube.
Which of the following situations does not show static equilibrium of liquids.
The figure below shows four situations in which a gray liquid and a black liquid (which we known nothing about) are in a U tube.
Which of the following situations does not show static equilibrium of liquids.
physics-General
physics-
An ideal monoatomic gas is carried around the cycle ABCDA as shown in the figure. The efficiency of the gas cycle is :
An ideal monoatomic gas is carried around the cycle ABCDA as shown in the figure. The efficiency of the gas cycle is :
physics-General
physics-
The initial state of an ideal gas is represented by the point a on the P-V diagram and its final state by the point e. The gas goes from the state a to the state e by three quasi stationary processes represented by
i) abe
ii) ace
iii) ade.
The heat absorbed by the gas is
The initial state of an ideal gas is represented by the point a on the P-V diagram and its final state by the point e. The gas goes from the state a to the state e by three quasi stationary processes represented by
i) abe
ii) ace
iii) ade.
The heat absorbed by the gas is
physics-General
physics-
The P.V. diagram of a certain process (Carnot cycle) is as shown in the figure.
The process is represented as
The P.V. diagram of a certain process (Carnot cycle) is as shown in the figure.
The process is represented as
physics-General
physics-
The following graphs shows two isotherms for a fixed mass of an ideal gas. The ratio of r.m.s. speed of the molecules at temperatures T1 and T2 is
The following graphs shows two isotherms for a fixed mass of an ideal gas. The ratio of r.m.s. speed of the molecules at temperatures T1 and T2 is
physics-General
physics-
A volume V-temperature T diagram was obtained when a given mass of gas was heated. During the heating process from state 1 to state 2, the pressure :
A volume V-temperature T diagram was obtained when a given mass of gas was heated. During the heating process from state 1 to state 2, the pressure :
physics-General
physics-
Two rods of same length and cross-sectional area are joined in series. Thermal conductivity of the rods are in ratio of 2 : 1.
The ends are maintained at temperatures qA and qB as shown with qA > qB and sides are thermally insulated.
Which of the following graph represents temperature gradient (dT/dx) against x in steady state
Two rods of same length and cross-sectional area are joined in series. Thermal conductivity of the rods are in ratio of 2 : 1.
The ends are maintained at temperatures qA and qB as shown with qA > qB and sides are thermally insulated.
Which of the following graph represents temperature gradient (dT/dx) against x in steady state
physics-General