Which of the following statement(s) is/are correct in the case of heavy water?
(a) Heavy water is used as a moderator in nuclear reactor.
(b) Heavy water is more effective as solvent than ordinary water.
(c) Heavy water is more associated than ordinary water.
(d) Heavy water has lower boiling point than ordinary water.
(a, c) Heavy water is used as a moderator in nuclear reactor and is more associated than ordinary water.
Dihydrogen reacts with dioxygen (02) to form water. Write the name and formula of the product when the isotope of hydrogen which has one proton and one neutron in its nucleus is treated with oxygen. Will the reactivity of both the isotopes be the same towards oxygen? Justify your answer.
Consider the reaction of water with F2 and suggest, in terms of oxidation and reduction, which species are oxidised/reduced ?
Why does H+ ion always get associated with other atoms or molecules?
(a) Ionisation enthalpy of hydrogen resembles that of alkali metals.
(b) Its reactivity is similar to halogens.
(c) It resembles both alkali metals and halogens.
(d) Loss of an electron from hydrogen atom results in a nucleus of very small size as compared to other atoms or ions. Due to small size it can not exist freely.
Do you expect different products in solution when aluminium (III) chloride and potassium chloride treated separately with (i) normal water (ii) acidified water (iii) alkaline water? Write equation wherever necessary.
Justify the position of hydrogen in the periodic table on the basis of its electronic configuration.
(a) How is dihydrogen prepared from water by using a reducing agent?
(b) Give the industrial use of dihydrogen which depends upon heat liberated when it bums.
Hardness of water may be temporary or permanent. Permanent hardness is due to the presence of
(a) Chlorides of Ca and Mg in water
(b) Sulphate of Ca and Mg in water
(c) Hydrogen carbonates of Ca and Mg in water
(d) Carbonates of alkali metals in water.
Which of the following statements are correct?
(a) Elements of group 15 form electron deficient hydrides.
(b) All elements of group 14 form electron precise hydrides.
(c) Electron precise hydrides have tetrahedral geometries.
(d) Electron rich hydrides can act as Lewis acids.
Which of the following statements are correct?
(a) Metallic hydrides are deficient of hydrogen.
(b) Metallic hydrides conduct heat and electricity.
(c) Ionic hydrides do not conduct electricity in solid state.
(d) Ionic hydrides are very good conductors of electricity in solid state.
Write chemical reactions to justify that hydrogen peroxide can function as an oxidising as well as reducing agent.
Which of the following statement(s) is/are correct in the case of heavy water?
(a) Heavy water is used as a moderator in nuclear reactor.
(b) Heavy water is more effective as solvent than ordinary water.
(c) Heavy water is more associated than ordinary water.
(d) Heavy water has lower boiling point than ordinary water.
If same mass of liquid water and a piece of ice are taken, then why is the density of ice less than that of liquid water?
What do you understand by the term ‘non-stoichiometric hydrides’? Do you expect this type of hydrides to be formed by alkali metals? Justify your answer.
Arrange the following:
(i) CaH2, BeH2 and TiH2 in order of increasing electrical conductance.
(ii) LiH, NaH and CsH in order of increasing ionic character.
(iii) H-H, D—D and F—F in order of increasing bond dissociation enthalpy.
(iv) NaH, MgH2 and H2O in order of increasing reducing property.
Describe the bulk preparation of dihydrogen by electrolytic method. What is the role of an electrolyte in this process?
Complete the following reactions:
(i)SiCl4 + LiAlH4 ————->
(ii)Mg3N2 + H2O ————->
(iii)NaH + CO —————–>
Which of the following hydrides is electron-precise hydride?
(a) B2H6
(b) NH3
(c) H20
(d) CH4
Which of the following equatibns depicts the oxidizing nature of H202?
(a) 2Mn0–4 + 6H+ + 5H202 → 2Mn2+ + 8H20 + 502
(b) 2Fe3+ + 2H+ + H202 → 2Fe2+ + 2H20 + 02
(c) 2I– + 2H+ + H202 → I2 + 2H20
(d) KI04 + H202 → KI03 + H20 + 02
Which of the following statements are not true for hydrogen?
(a) It exists as diatomic molecule.
(b) It has one electron in the outermost shell.
(c) It can lose an electron to form a cation which can freely exist.
(d) It forms a large number of ionic compounds by losing an electron.
Dihydrogen can be prepared on commercial scale by different methods. In its preparation by the action of steam on hydrocarbons, a mixture of CO and H2 gas is formed. It is known as _____ .
(a)water gas
(b) syn gas
(c) producer gas
(d) industrial gas
How is heavy water prepared? Compare its physical properties with those of ordinary water.
Rohan heard that instructions were given to the laboratory attendant to store a particular chemical, i.e., keep it in the dark room, add some urea in it, and keep it away from dust. This chemical acts as an oxidizing as well as a reducing agent in both acidic and alkaline media. This chemical is important for use in the pollution control treatment of domestic and industrial effluents.
(i) Write the name of this compound.
(ii) Explain why such precautions are taken for storing this chemical.
Discuss the consequences of high enthalpy of H-H bond, in terms of chemical reactivity of dihydrogen.
What do you understand by (i) Electron-deficient (ii) Electron-precise (iii) Electron-rich compounds of hydrogen? Provide justification with suitable examples.
Among NH3 H2O and HE, which would you expect to have highest magnitude of hydrogen bonding and why?
Complete the following chemical reactions.
(i) PbS(s) + H2O2 (aq) ————->
(ii) MnO4– (aq) + H2O2 (aq) ————->
(iii) CaO(s) + H2O(g) ————->
(iv) AlCl3(g) + H2O(l)————->
(v) Ca3N2(S) + H2O(l) ————->
Classify the above into (a) hydrolysis, (b) redox and (c) hydration reactions.
Is demineralised or distilled water useful for drinking purposes? If not, how can it be made useful ?
Knowing the properties of H2O and D2O, do you think D2O can be used for drinking purpose.
Which gas is evolved when Mg3N2 (Magnesium nitride) is treated with H2O? Give chemical reaction.
Explain the following:
(i) Temporary hardness can remove by boiling
(ii) Soft water lathers with soap but hard water not.
Hydrogen peroxide is obtained by‘the electrolysis of _______.
(a) water
(b) sulphuric acid
(c) hydrochloric acid
(d) fused sodium peroxide
Which of the following reactions is an example of use of water gas in the synthesis of other compounds?
