Goyal Brother Class-9 Hydrogen Study of the First Element Ch-6 Solutions. We Provide Answer related Occurrence , Lab Preparation, Physical and Chemical properties, Uses of Hydrogen Visit official Website CISCE for detail information about ICSE Board Class-9.
Goyal Brother Class-9 Hydrogen Study of the First Element Ch-6
| Board | ICSE |
| Publications | Goyal Brother Prakashan |
| Subject | Chemistry |
| Class | 9th |
| Writer | Dr. S.K. Aggarwal |
| Chapter-6 | Study of the First Element-Hydrogen |
| Topics | Solutions of Exercises |
| Edition | for 2022-2023 Academic Session |
Goyal Brother Class-9 Hydrogen Study of the First Element
Ch-6 ICSE Solutions
(Page- 131)
Questions 1.
(a) Name two metals which react with cold water to form hydrogen. Write the balanced chemical equations.
(b) Name two metals which react with steam and displace hydrogen. Write the balanced chemical equations.
Answer :
(a) sodium and potassium .
2K + 2H2O → 2KOH + H2.
2Na + 2H2O → 2NaOH + H2.
(b) Magnesium, Aluminum
Mg + H2O → MgO+ H2.
2Al + 3H2O → Al2O3+ H2.
Questions 2. Amongst the metals iron, magnesium, zine and aluminum, which reacts
(a) fastest with dil. sulphuric acid and
(b) slowest with dilute sulphuric acid. Write fully balanced chemical equations.
Answer :
(a) Magnesium reacts Fastest with dil. sulphuric acid
(b) Zinc reacts Slowest with dil. sulphuric acid
Questions 3. Name two metals which will displace hydrogen from strong caustic alkalies. Write chemical equations in support of your answer.
Answer : Na and K are highly reactive active metals and are present on top of activity series so they can displace hydrogen by reaction with water
Questions 4. How do the following react with water? Write balanced chemical equations
(a) Potassium hydride—KH(s)+H2O(l)→H2(g)+K⊖(aq)+OOH(aq)
(b) Calcium hydride.—CaH2+2H2O→Ca(OH)2+2H2.
Questions 5. How will you prepare hydrogen gas in laboratory’? State three precautions necessary for the collection of hydrogen.
Answer : Hydrogen is prepared in the laboratory by the action of the dilute hydrochloric acid or dilute sulphuric acid on granulated zinc. Granulated zinc gives more surface area for the acid to act, so hydrogen is formed faster
Questions 6.
(a) why does hydrogen gas collected from zinc has a characteristic fishy smell?
(b) Name the chemicals used in the purification of hydrogen gas prepared from granulated zinc.
Answer :
(a) Granulated zinc contains traces of zinc phosphide. The zinc phosphide reacts with dilute sulphuric acid to liberate phosphine gas, which has a fishy smell.
(b) Silver nitrate solution(AgNO3), lead nitrate solution [Pb(NO3)2], potassium hydroxide solution (KOH) and anhydrous calcium chloride (CaCl2) solutions are used in the purification of hydrogen gas prepared from granulated zinc
Questions 7. How is hydrogen prepared industrially by Bosch Process?
Answer : Preparation of hydrogen by Bosch’s process Industrially, hydrogen is prepared by passing steam over red-hot coke at high temperature. The products are CO and hydrogen. This mixture of carbon monoxide and hydrogen is called is called water gas
Questions 8. K, Na, Ca, Mg, Al, Zn, Fe, Sn, Pb, H, Cu, Hg. Ag and Au constitute activity series. Answer the followang questions:
(a) Name the metal which reacts fastest with cold water–Na
(b) Name the metal which does not react with cold water, but reacts with boiling hot water very slowly.–Ca
(c) Name the metal which on heating reacts with steam, but reaction is reversible.–Fe
(d) Name a metal which reacts explosively with dilute HCL–K
(e) Name a metal which reacts vigorously with dilute HCI.-Zn
(f) Name a metal which displaces hydrogen very slowly from dilute HCL.–Fe
(g) Name a metal which does not react with water or dilute HCI.–Pb
Questions 9. By giving examples explain the following terms:
(a) Oxidation reaction—Oxidation reaction is a chemical reaction in which oxygen is added to or hydrogen is removed from an element, molecule or a compound
(b) Reduction reaction—A reduction reaction is a chemical reaction in which oxygen is removed or hydrogen is added to an element, molecule, or compound.
— End of Goyal Brother Class-9 Hydrogen Study of the First Element Ch-6 Solutions:–
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