Tag: urea

Quizzes (1) Questions (18)

Questions Related to urea

Multiple choice urea organic compounds with functional group containing nitrogen

First step of urea manufacture is $2NH _3 \ + \ CO _2 \rightleftharpoons X$
Compound $X$ is:

  1. $NH _2COONH _4$
  2. $NH _2COOH$
  3. $NH _4COOH$
  4. Both $A$ and $B$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The first is carbamate formation: the fast exothermic reaction of liquid ammonia with gaseous carbon dioxide at high temperature and pressure to form ammonium carbamate (${ H } _{ 2 }N-COO-N{ H } _{ 4 }$).

 $2N{ H } _{ 3 }+C{ O } _{ 2 }\rightleftharpoons { H } _{ 2 }N-COO-N{ H } _{ 4 }$

Multiple choice urea organic compounds with functional group containing nitrogen

Urea is a  ___________ fertilizer

  1. nitrogeneous

  2. potassium

  3. phosphotic

  4. natural
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

More than 90% of world industrial production of urea is destined for use as a nitrogen-release fertilizer. Urea has the highest nitrogen content of all solid nitrogenous fertilizers in common use. Therefore, it has the lowest transportation costs per unit of nitrogen nutrient.

Multiple choice urea organic compounds with functional group containing nitrogen

What is the name of the compound $NH _2COONH _4$?

  1. Diammonium carbonate

  2. Ammonium carbamate

  3. Uric acid
  4. Both $B$ and $C$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ammonium carbamate is a salt formed by the reaction of ammonia with carbon dioxide or carbamic acid. This compound is a white solid that is extremely soluble in water, soluble in alcohol, and only slightly volatile at room temperature. It is prepared by the direct reaction between liquid ammonia and dry ice (solid carbon dioxide).

Multiple choice urea organic compounds with functional group containing nitrogen

Biuret formation in urea is kept at minimum (< 1 %), because it is:

  1. toxic and harmful to some crops

  2. corrosive in nature

  3. helpful in the decomposition of urea

  4. explosive in nature
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Biuret is a chemical compound with the chemical formula ${ C } _{ 2 }{ H } _{ 5 }{ N } _{ 3 }{ O } _{ 2 }$. It is also known as carbamylurea. It is the result of condensation of two molecules of urea and is an impurity in urea-based fertilizers.

The most common impurity of synthetic urea is biuret, which impairs plant growth. Biuret is undesirable in fertilizer urea because it is toxic to crop plants, although to what extent depends on the nature of the crop and the method of application of the urea.

Multiple choice urea organic compounds with functional group containing nitrogen

Dehydration of ammonium carbamate produces:

  1. biuret

  2. ammonia water

  3. urea

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The ability of ammonium carbamate to make urea was first discovered in 1870 by Bassarov when he heated ammonium carbamate in sealed glass tubes at temperatures ranging from 130 to 140 $℃$. This yields urea and water in an equimolar ratio. A typical industrial plant that makes urea can produce up to 1500 tons a day. Ammonia and carbon dioxide is excessively fed to a synthesis reactor in this process. Ammonium carbamate is produced as an intermediate in this reactor and can then be dehydrated to urea according to the following equation.

${ H } _{ 2 }N-COON{ H } _{ 4 }→N{ H } _{ 2 }CON{ H } _{ 2 }+{ H } _{ 2 }O$

Multiple choice urea organic compounds with functional group containing nitrogen

Wohler's synthesis is used for the preparation of :

  1. Glycine

  2. Amino acids

  3. Urea

  4. Proteins
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Wohler's synthesis is used for the preparation of urea. In this reaction ammonium cyanate is transformed into urea.
$\displaystyle NH _4(NCO) \rightarrow NH _3 + HNCO \rightarrow (NH _2) _2CO$

Multiple choice urea organic compounds with functional group containing nitrogen

__________ is the undesirable by-product produced in the manufacture of urea.

  1. Biuret

  2. Ammonium carbonate

  3. Carbon dioxide

  4. Ammonium carbamate
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Biuret is a chemical compound with the chemical formula ${ C } _{ 2 }{ H } _{ 5 }{ N } _{ 3 }{ O } _{ 2 }$. It is also known as carbamylurea. It is the result of condensation of two molecules of urea and is an impurity in urea-based fertilizers.

The most common impurity of synthetic urea is biuret, which impairs plant growth. Biuret is undesirable in fertilizer urea because it is toxic to crop plants, although to what extent depends on the nature of the crop and the method of application of the urea.

Multiple choice urea organic compounds with functional group containing nitrogen

Which of the following fertilisers is used as a cattle feed?

  1. Superphosphate

  2. Calcium ammonium nitrate

  3. Urea

  4. Ammonium sulphate
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When soybean meal and other plant proteins are high in price, more urea is used to replace plant protein in the ration of beef cattle and sheep. Urea is a non-protein nitrogen (NPN) compound.