In the preparation of hydrogenated oil the chemical reaction involving hydrogen is called:
(a) hydrogenation
(b) reduction
(c) dehydration
(d) oxidation
Concept Videos :-
Concept Questions :-
(a)
- Necessity for Hydrogenation • Hydrogenated fat is basically a substitute to butter fats. • High costs of butter fat and its poor storage stability were detrimental factors that led to the investigation of alternative sources of hard fats. • This investigation led to the invention of catalyzed H2 addition across unsaturated sites of oils and fats and was quickly commercialized. • Conversion of liquid oils to solid and semi-solid fats having wide spectrum of physical & chemical characteristics of products were thus obtained.
- What is Hydrogenation? • Hydrogenation is a process that reduces unsaturated fatty acid content of triglycerides by attaching hydrogen atoms at the point of unsaturation in the presence of catalyst, usually Nickel. • Hydrogenation accomplishes two things-: • 1.It increases the melting point of the oil or fat. • 2.Resistance to oxidation and flavor deterioration. • Hydrogenation process depends on several parameters: • Pressure, Temperature, Type of catalyst, Speed of agitation etc.
- MECHANISM • The mechanism involved in fat hydrogenation is believed to be the reaction between unsaturated liquid oil and atomic hydrogen adsorbed on a metal catalyst. • It is similar to hydrogenation of alkenes.
Difficulty Level:
The most abundant isotope of hydrogen is:
(a) tritium
(b) deuterium
(c) protium
(d) para-hydrogen
Concept Videos :-
Concept Questions :-
(c) Protium is 1H1.
Difficulty Level:
Hydrogen is evolved by the action of cold dilute HNO3 on:
(a) Fe
(b) Mg or Mn
(c) Cu
(d) Al
Concept Videos :-
Concept Questions :-
(b) Only Mg and Mn react with cold dil. HNO3 to give H2.
Difficulty Level:
A molten ionic hydride on electrolysis gives:
(a) H+ ion moving towards the cathode
(b) H+ ion moving towards the anode
(c) H2 is liberated at anode
(d) H2 is liberated at cathode
Concept Videos :-
Concept Questions :-
(c) Ionic hydride has H- ion.
Difficulty Level:
Which statement is not correct for hydrogen peroxide ?
(a) Pure H2O2 is fairly stable
(b) It sometimes acts as a reducing agent
(c) It acts as an oxidising agent
(d) Aqueous solution of H2O2 is weakly basic
Concept Questions :-
(d) H2O2 is weak di-basic acid
Difficulty Level:
In solid hydrogen, the intermolecular bonding is:
(a) ionic
(b) van der Waals'
(c) metallic
(d) covalent
Concept Videos :-
Concept Questions :-
(b) Covalent molecules occupy solid structure due to increasing van der Waals' forces.
Difficulty Level:
The lightest gas is :
(a) nitrogen
(b) helium
(c) oxygen
(d) hydrogen
Concept Videos :-
Concept Questions :-
(d) H2 has lowest molecular weight.
Difficulty Level:
The critical temperature of water is higher than that of O2 because H2O molecule has:
(a) fewer electrons than oxygen
(b) two covalent bonds
(c) V-shape
(d) dipole moment
Concept Videos :-
Concept Questions :-
(d) Dipole-dipole attraction give rise to more tendency for aggregation.
Difficulty Level:
Benzene is oxidized by H2O2 in presence of FeSO4 to:
(a) phenol
(b) cyclohexane
(c) benzaldehyde
(d) benzoic acid
Concept Questions :-
(a)
Difficulty Level:
The oxidizing property of H2O2 is best explained by assuming that two oxygen atoms in its molecule are:
(a) bonded differently
(b) bonded similarly
(c) bonded covalently
(d) bonded by hydrogen bonds
Concept Questions :-
(a) It is a fact
Difficulty Level: