Class 11th Chemistry - Hydrogen Case Study Questions and Answers 2022 - 2023
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QB365 provides a detailed and simple solution for every Possible Case Study Questions in Class 11 Chemistry Subject - Hydrogen, CBSE. It will help Students to get more practice questions, Students can Practice these question papers in addition to score best marks.
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Hydrogen Case Study Questions With Answer Key
11th Standard CBSE
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Reg.No. :
Chemistry
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Hydrogen is most abundant element in universe. It exist in combined state in form of H2 O. On industrial scale, it is prepared by water gas shift reaction from petrochemicals. It is also obtained as a by-product of the electrolysis of brine. It has high bond dissociation enthalpy due to which it is less reactive. It forms hydrides with almost all elements. The hydrides are of three types, ionic, covalent and metallic or non-stoichiometric hydrides. It acts as reducing as well as oxidising agent. Its compound H2 O is essential for life. H2 O2 acts as oxidising, bleaching, as well reducing agent. D2 O(Heavy water is used as coolant in nuclear reactors).
(a) A 5.0 cm3 solution of H2 O2 liberates 0.508 g of iodine from KI solution. Calculate the strength of H2 O2 solution in terms of volume strength at STP.
(b) What is volume of oxygen liberated at STP from 15 mL of 20 vol. of H2 O2 of STP.
(c) How is water gas produced?
(d) What happens when steam is passed over water gas in presence of catalyst in water gas shift reaction.
The molecular formula of commercial resin used for exchange in water softening is C8H7SO3Na(Mol. Wt-206). What would be maximum uptake of Ca2 + ions by resin in mol per gram of resin?
(f) Write ionic reduction of H2O2 when it acts as reducing agent in basic medium.
What is false about H2O2?
(a) Acts as both oxidising as well as reducing agent
(b) Both OH bonds lie in same plane
(c) Pale blue liquid.
(d) Can be reduced by O3.(a) -
Study the table and answer the questions that follow based in this table and related studied concepts.
Physical Properties of H2O and D2 O.Property H2O D2 O Molecular mass (g mol-1) 18.0151 20.0276 Melting point/K 273.0 276.8 Boiling point/K 373.0 374.4 Enthalpy of formation/kJ mol-1 -285.9 -294.6 Enthalpy of vaporisation (373K)/kJ mol-1 40.66 41.61 Enthalpy of fusion/kJ mol-1 6.01 - Temp of max. density/K 276.98 284.2 Density (298K)/g cm-3 1.0000 1.1059 Viscosity/centipoise 0.8903 1.107 Dielectric constaat/C2/N .m2 78.39 78.06 Electrical conductivity (293K/ohm-1 cm-1 ) 5.7x 10-8 - (a) At what temperature heavy water has maximum density?
(b) What is use of heavy water?
(c) Why is water responsible for moderation of climate and body temperature of living beings?
(d) Why is boiling point of D2 O higher than H2O?
(e) What happens when Mg3N2 reacts with D2O?
(f) What is the formula of Deuterium sulphate?
(g) What happens when aluminium carbide reacts with water?(a)
Case Study
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Answers
Hydrogen Case Study Questions With Answer Key Answer Keys
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(a) H2O2 + H2SO4 + 2KI \(\longrightarrow\)l2+ K2SO 4 + 2H2O
34 254
254 g of l2 is liberated from 34 g of H2O2.
0.508 g of l2 is liberated \(=\frac{34}{254} \times 0.508=\) = 0.068 g H2O2
5 mL of H2O2 contains 0.068 g of H2O2
1 mL of H2O2 contain \(\frac{0.068}{5}\) g of H2O2
2 H2O2 \(\longrightarrow\) 2H2O + O2
68 g 22.4 L at STP
68 g of H2O2 produces 22400 mL g O2 at STP
\(\frac{0.068}{5}\) g of H2O2 produces = \(\frac{22400}{68} \times \frac{68}{1000 \times 5}\) = 4.48 mL of STP
Volume strength of H2O2 = 4.48 volume.
(b) 1 mL of H2O2 (20 vol.) liberates 20 mL of O2 at STP
15 mL of H2O2 (20 vol.) liberates = 20 x 15 = 300 mL of O2 at STP.
(c) It is produced by passing steam over red hot coke
C + H2O (steam) \(\stackrel{\Delta}{\longrightarrow} \) CO + H2 .
coke water gas.
(d) CO gets oxidised to CO2 with steam followed by absorption of CO2 in alkali and H2 is separated.
(e) \(\mathrm{Ca}^{2+}+2 \mathrm{C}_{8} \mathrm{H}_{7} \mathrm{SO}_{3} \mathrm{Na} \longrightarrow\left(\mathrm{C}_{8} \mathrm{H}_{7} \mathrm{SO}_{3}\right)_{2} \mathrm{Ca}+2 \mathrm{Na}^{+}\)
412 g of resin takes up 1 mole of Ca2+.
1 g of resin takes up = \(\frac{1}{412} \) mole of Ca2+= 0.0024 moles of Ca2+ ion.
(f) H2 O2 + 2OH- \(\longrightarrow\) O2 + 2H2 O + 2e-
(g) (b) Both OH bonds lie in same plane. This is false. -
(a) 284.2 K
(b) It is used as coolant and moderator in nuclear reactor.
(c) It is due to high heat of vapourisation and heat capacity of water.
(d) It is due to higher molar mass, it has more intermolecular forces of attraction.
(e) Mg(OD)2 and ND3 (Deutero-ammonia) is formed
Mg3N2 + 6D2O \(\longrightarrow \) 3Mg(OD)2 + 2ND3
(f) D2SO4
(g) Deutero methane and Aluminium deuteroxide is formed
Al4C3 + 12D2O \(\longrightarrow\) AI(OD)3 + 3CD4.
Case Study
