Chemistry

Hydrogen

Question:

How can the production of dihydrogen obtained from ‘Coal gasification’ be increased?

Answer:

The production of dihydrogen in coal gasification can be increased by reacting CO(y) present in syngas with steam in the presence of iron chromate catalysts.
cbse-class-11th-chemistry-solutions-chapter-9-hydrogen-2
With the removal of C02 the reaction shifts in the forward direction and thus, the production of dihydrogen will be increased.

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Hydrogen

Q 1.

Show how H2O2 junctions both as a reducing and as an oxidising agent.

Q 2.

Describe the usefulness of water in biosphere and biological systems.

Q 3.

Which type of hydrides are generally non-stoichiometric in nature?

Q 4.

Complete the following reactions:
cbse-class-11th-chemistry-solutions-chapter-9-hydrogen-23

Q 5.

Which of the following equatibns depicts the oxidizing nature of H202?
(a) 2Mn04 + 6H+ + 5H202 → 2Mn2+ + 8H20 + 502
(b) 2Fe3+ + 2H+ + H202 → 2Fe2+ + 2H20 + 02
(c) 2I + 2H+ + H202 → I2 + 2H20
(d) KI04 + H202 → KI03 + H20 + 02

Q 6.

What type of elements form interstitial hydrides?

Q 7.

Give two advantages of using hydrogen over gasoline as a fuel.

Q 8.

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?

Q 9.

What is the cause of bleaching action of H2O2?

Q 10.

How is  heavy water prepared? Compare its physical properties with those of ordinary water.

Q 11.

Name a substance which can oxidise H2O2

Q 12.

Some of the properties of water are described below. Which of them is/are not correct?
(a) Water is known to be universal solvent.
(b) Hydrogen bonding is present to a large extent in liquid water.
(c) There is no hydrogen bonding in the frozen state of water.
(d) Frozen water is heavier than liquid water.

Q 13.

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.

Q 14.

Explain the following:
(i) Temporary hardness can remove by boiling
(ii) Soft water lathers with soap but hard water not.

Q 15.

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.

Q 16.

How can saline hydrides remove traces of water from organic compounds?

Q 17.

What is water gas? How is it prepared?

Q 18.

How do you expect the metallic hydrides to be useful for hydrogen storage? Explain.

Q 19.

Discuss the principle and method of softening of hard water by synthetic ion-exchange resins.

Q 20.

Write two uses of interstitial hydrides.

Q 21.

What is the use of hydrogen in the manufacture of Vanaspati Ghee?

Q 22.

Name the classes of hydrides to which H20, B2H6 and NaH belong.

Q 23.

Write one chemical reaction for the preparation of D202.

Q 24.

Write the names of isotopes of hydrogen. What is the mass ratio of these isotopes?

Q 25.

What is meant by ‘demineralised water’ and how can it be obtained?

Q 26.

What is the importance of heavy water with regard to nuclear power generation ?

Q 27.

What is zeolite?

Q 28.

Which compounds cause temporary hardness of water?

Q 29.

Complete the following reactions:
(i)SiCl4 + LiAlH4 ————->
(ii)Mg3N2 + H2O ————->
(iii)NaH + CO —————–>

Q 30.

Which of the following statements are correct?
(a) Hydrides of group 13 act as Lewis acids.
(b) Hydrides of group 14 are electron deficient hydrides.
(c) Hydrides of group 14 act as Lewis acids.
(d) Hydrides of group 15 act as Lewis bases.

Q 31.

Discuss briefly de-mineralisation of water by ion exchange resin.

Q 32.

How can the production of dihydrogen obtained from ‘Coal gasification’ be increased?

Q 33.

What causes the temporary and permanent hardness of water?

Q 34.

Account for the following:
(a) Can phosphorus with electronic configuration 3s2 3p3 form PH5?
(b) Water is responsible for moderation of body temperature. How?
(c) Hard water is not suitable for boilers as well as for laundary.

Q 35.

What are metallic/interstitial hydrides? How do they differ from molecular hydrides?

Q 36.

Calculate the strength of 5 volume H202

Q 37.

(i)Draw the gas phase and solid phase structure of H202.
(ii) H202 is a better oxidizing agent than water. Explain.

Q 38.

Give an example of an ionic hydride and a covalent hydride:

Q 39.

The aqueous solution of H2O2 is acidic in nature. Explain with the help of example. Name two substances which catalyse the decomposition reaction of H2O2.

Q 40.

Can we use concentrated sulphuric acid and pure zinc in the preparation of dihydrogen?Write the chemical reactions to show the amphoteric nature of water. Why is hydrogen peroxide  stored in wax-lined plastic coloured bottles ?

Q 41.

Explain why HC1 is a gas and HF is a liquid.

Q 42.

Justify the position of hydrogen in the periodic table on the basis of its electronic configuration.

Q 43.

Why does hydrogen occur in a diatomic form rather than in a monoatomic form under normal conditions?

Q 44.

Saline hydrides are known to react with water violently producing fire. Can C02, a well known fire extinguisher, be used in this case? Explain.

Q 45.

The oxide that gives H202 on treatment with dilute H2S04 is
(a) Pb02
(b) Ba02 -8H20
(c) Mn02
(d) Ti02

Q 46.

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.

Q 47.

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.

Q 48.

What do you understand by the term ‘auto-protolysis of water? What is its significance?

Q 49.

When sodium peroxide is treated with dilute sulphuric acid, we get .
(a) sodium sulphate and water
(b) sodium sulphate and oxygen
(c) sodium sulphate, hydrogen and oxygen
(d) sodium sulphate and hydrogen peroxide.

Q 50.

How can production of hydrogen from water gas be increased by using water gas shift reaction?