In the preparation of hydrogenated oil the chemical reaction involving hydrogen is called:
The most abundant isotope of hydrogen is:
(c) Protium is 1H1.
Hydrogen is evolved by the action of cold dilute HNO3 on:
(b) Mg or Mn
(b) Only Mg and Mn react with cold dil. HNO3 to give H2.
Hydrogen is not obtained when zinc reacts with:
(a) cold water
(b) dil. H2SO4
(c) dil HCl
(d) hot 20% NaOH
(a) Elements having reduction potential of -0.41V or below can liberate hydrogen from cold water. Such as alkali metals Ba, Sr and Ca.
Also Zn-Cu and Al-Hg couples liberate hydrogen with cold water.
Very pure hydrogen (99.9%) can be made by which of the following processes ?
(a) Mixing natural hydrocarbons of high molecular weight
(b) Electrolysis of water
(c) Reaction of salt like hydrides with water
(d) Reaction of methane with steam
(c) Hydrogen of high purity is obtained by electrolysing aqueous barium hydroxide in presence of Ni electrodes.
Which of the following pairs will not produce dihydrogen gas ?
(a) Cu + HCl (dil.)
(b) Fe + H2SO4
(c) Mg + steam
(d) Na + alcohol
(a) Cu has lesser than H.
The metal that does not displace hydrogen from an acid is:
(a) Hg is placed below H in electrochemical series.
The catalyst used in Bosch process of manufacture of H2 is:
(a) finely divided Ni
(d) Fe2O3 + Cr2O3
In this process water gas (CO + H2, prepared from coal and water at 1270 K) is mixed with two times its volume of steam passed over catalyst Fe2O3, in the presence of promoter Cr2O3 or ThO2 at 773 K giving products CO2 and H2.
CO2 is dissolved in water under pressure (20 to 25 atm) and is removed leaving behind un dissolved H2.
In which reaction hydrogen is not formed ?
(1) Copper and hydrochloric acid
(2) Iron and sulphuric acid
(3) Magnesium and steam
(4) Sodium and alcohol
(1) Copper is placed below hydrogen in electrochemical series. Hence it does not librate hydrogen gas with hydrochloric acid.
Hydrogen will not reduce
(A) heated cupric oxide
(B) heated ferric oxide
(C) heated stannic oxide
(D) heated aluminium oxide
(D). AlO bond is very strong.