Asked | Gurucool - Coolfluencing the world

Q11
Write balanced chemical equations for the following processes :
(i) XeF₂ undergoes hydrolysis.
(ii) MnO₂ is heated with conc. HCl.
OR
Arrange the following in order of property indicated for each set :
(i) H₂O, H₂S, H₂Se, H₂Te – increasing acidic character
(ii) HF, HCl, HBr, HI – decreasing bond enthalpy.

Free Response Question Hard View solution

Q12
An element crystallizes in fcc lattice with a cell edge of 300 pm. The density of the element is 10.8 g cm⁻³. Calculate the number of atoms in 108 g of the element.

Free Response Question Medium View solution

Q13
A 4% solution(w/w) of sucrose (M = 342 g/mol) in water has a freezing point of 271.15 K. Calculate the freezing point of 5% glucose (M = 180 g/mol) in water.
(Given: Freezing point of pure water = 273.15 K)

Free Response Question Hard View solution

Q14
The decomposition of NH₃ on platinum surface is zero order reaction. If rate constant (k) is 4×10⁻³ Ms⁻¹, how long will it take to reduce the initial concentration of NH₃ from 0.1 M to 0.064 M.

Free Response Question Medium View solution

Q15
(i) What is the role of activated charcoal in a gas mask?
(ii) A colloidal sol is prepared by the given method in the figure. What is the charge on hydrated ferric oxide colloidal particles formed in the test tube? How is the sol represented?
img alt=src="" style="height:155px; width:135px
(iii) How does chemisorption vary with temperature?

Free Response Question Medium View solution

Q16
(i) Write the role of ‘CO’ in the purification of nickel.
(ii) What is the role of silica in the extraction of copper ?
(iii) What type of metals are generally extracted by electrolytic method?

Free Response Question Medium View solution

Q17
Give reasons for the following :
(i) Transition metals form alloys.

(ii) Mn₂O₃ is basic whereas Mn₂O₇ is acidic.

(iii) Eu²⁺ is a strong reducing agent.

Free Response Question Medium View solution

Q18
(i) Why bithional is added in soap ?

(ii) Why magnesium hydroxide is a better antacid than sodium bicarbonate ?

(iii) Why soaps are biodegradable whereas detergents are non-biodegradable ?
OR
Define the following terms with a suitable example in each :
(i) Antibiotics
(ii) Artificial sweeteners
(iii) Analgesics

Free Response Question Medium View solution

Q19
Write the structures of main products when benzene diazonium chloride reacts with the following reagents :
(i) CuCN
(ii) CH₃CH₂OH
(iii) KI

Free Response Question Hard View solution

Q20
Out of (CH₃)₃C–Br and (CH₃)₃C–I, which one is more reactive towards SN1 and why ?

(ii) Write the product formed when p-nitrochlorobenzene is heated with aqueous NaOH at 443 K followed by acidification.
(iii) Why dextro and laevo – rotatory isomers of Butan-2-ol are difficult to separate by fractional distillation ?

Free Response Question Hard View solution

Class 6	Science Mathematics Social Science	English Hindi Computer
Class 7	Science Mathematics Social Science	English Hindi Computer
Class 8	Science Mathematics Social Science	English Hindi Computer
Class 9	Science Mathematics Social Science	English Hindi Computer
Class 10	Science Math Social Science	English Hindi Computer
Class 11	Physics Chemistry Biology	Mathematics English Economics
Class 12	Physics Chemistry Biology	Mathematics English Economics
Class 5	EVS
College Entrance	Jamia Millia Islamia Aligarh Muslim University Banaras Hindu University

2019

Solution

Q12
An element crystallizes in fcc lattice with a cell edge of 300 pm. The density of the element is 10.8 g cm⁻³. Calculate the number of atoms in 108 g of the element.

Solution

Q13
A 4% solution(w/w) of sucrose (M = 342 g/mol) in water has a freezing point of 271.15 K. Calculate the freezing point of 5% glucose (M = 180 g/mol) in water.
(Given: Freezing point of pure water = 273.15 K)

Solution

Q14
The decomposition of NH₃ on platinum surface is zero order reaction. If rate constant (k) is 4×10⁻³ Ms⁻¹, how long will it take to reduce the initial concentration of NH₃ from 0.1 M to 0.064 M.

Solution

Solution

Q16
(i) Write the role of ‘CO’ in the purification of nickel.
(ii) What is the role of silica in the extraction of copper ?
(iii) What type of metals are generally extracted by electrolytic method?

Solution

Q17
Give reasons for the following :
(i) Transition metals form alloys.

(ii) Mn₂O₃ is basic whereas Mn₂O₇ is acidic.

(iii) Eu²⁺ is a strong reducing agent.

Solution

Solution

Q19
Write the structures of main products when benzene diazonium chloride reacts with the following reagents :
(i) CuCN
(ii) CH₃CH₂OH
(iii) KI

Solution

Solution

Subjects

2019

Solution

Q12 An element crystallizes in fcc lattice with a cell edge of 300 pm. The density of the element is 10.8 g cm⁻³. Calculate the number of atoms in 108 g of the element.

Solution

Q13 A 4% solution(w/w) of sucrose (M = 342 g/mol) in water has a freezing point of 271.15 K. Calculate the freezing point of 5% glucose (M = 180 g/mol) in water. (Given: Freezing point of pure water = 273.15 K)

Solution

Q14 The decomposition of NH₃ on platinum surface is zero order reaction. If rate constant (k) is 4×10⁻³ Ms⁻¹, how long will it take to reduce the initial concentration of NH₃ from 0.1 M to 0.064 M.

Solution

Solution

Q16 (i) Write the role of ‘CO’ in the purification of nickel. (ii) What is the role of silica in the extraction of copper ? (iii) What type of metals are generally extracted by electrolytic method?

Solution

Q17 Give reasons for the following : (i) Transition metals form alloys. (ii) Mn₂O₃ is basic whereas Mn₂O₇ is acidic. (iii) Eu²⁺ is a strong reducing agent.

Solution

Solution

Q19 Write the structures of main products when benzene diazonium chloride reacts with the following reagents : (i) CuCN (ii) CH₃CH₂OH (iii) KI

Solution

Solution

Subjects

Q12
An element crystallizes in fcc lattice with a cell edge of 300 pm. The density of the element is 10.8 g cm⁻³. Calculate the number of atoms in 108 g of the element.

Q13
A 4% solution(w/w) of sucrose (M = 342 g/mol) in water has a freezing point of 271.15 K. Calculate the freezing point of 5% glucose (M = 180 g/mol) in water.
(Given: Freezing point of pure water = 273.15 K)

Q14
The decomposition of NH₃ on platinum surface is zero order reaction. If rate constant (k) is 4×10⁻³ Ms⁻¹, how long will it take to reduce the initial concentration of NH₃ from 0.1 M to 0.064 M.

Q16
(i) Write the role of ‘CO’ in the purification of nickel.
(ii) What is the role of silica in the extraction of copper ?
(iii) What type of metals are generally extracted by electrolytic method?

Q17
Give reasons for the following :
(i) Transition metals form alloys.

(ii) Mn₂O₃ is basic whereas Mn₂O₇ is acidic.

(iii) Eu²⁺ is a strong reducing agent.

Q19
Write the structures of main products when benzene diazonium chloride reacts with the following reagents :
(i) CuCN
(ii) CH₃CH₂OH
(iii) KI