Sub. code 301
NEB — GRADE XI
CDC
Model Question
Class 11 Chemistry Model Question CDC
The candidates are required to give their answers in their own words as far as practicable. The figures in the margin indicate full marks.
Pass Marks : 32
सबै प्रश्नको उत्तर दिनुहोस् । (Attempt All Questions)
This model question paper is for Class 11 Chemistry, CDC (subject code 301), carrying full marks of 75 with a pass mark of 32, to be completed within 3 Hours. Model answers are available for questions that have one — reveal them with a free account (a few reveals) or a paid plan (unlimited).
Group 'A'
Very short answer to the following questions.
How many atoms are there in two molecules of water?
a. 3
b. 4
c. 5
c. 6
What is the number of moles of ammonia gas formed when 0.5 mole of nitrogen gas is reacted with excess of hydrogen gas?
a. 0.5
b. 1
c. 2
c. 3
Which of the following bonding is responsible for the solubility of ammonia gas in water?
a. Hydrogen bonding
b. Ionic bonding
c. Covalent bonding
d. Van der Waal's force
What happens when sulphur dioxide () gas is passed through an acidified solution of hydrogen sulphide () gas?
a. is oxidized to sulphur
b. is reduced to sulphur
c. is oxidized to
d. is reduced to Sulphur
Which of the following property of crystalline substance describe the similar chemical composition?
a. Isotopism
b. Polymorphism
c. Allotropism
d. Isomorphism
gas is formed as an intermediate during the manufacture of sulphuric acid by Contact process. The formation of sulphur trioxide from sulphur dioxide and oxygen is reversible.
Which conditions of pressure and temperature favour the reverse reaction?
a. High pressure and high temperature
b. High pressure and low temperature
c. Low pressure and high temperature
d. Low pressure and low temperature
Which is the correct order of ease of carbon dioxide production by heating the Group II metal carbonates?
a.
b.
c.
d.
Which of the following is related to Batch process?
a. Required high cost equipment
b. Cannot be controlled easily
c. Generally available in fully automated plant
d. Involves sequence of steps followed in specific order
Sodium-glucose pump is an example of
a. Primary active transport protein
b. Secondary active transport protein
c. Primary passive transport protein
d. Secondary passive transport protein
An intermediate compound is formed during the production of urea through ammonia/carbon dioxide technology. What is the molecular formula of ?
a.
b.
c.
d.
Which of the following are recycled in the manufacture of sodium carbonate by Solvay's process?
a. and
b. and
c. and
d. and
Group 'B'
Give short answer to the following questions.
An element X has 2 electrons in K shell, 8 electrons in L shell and 5 electrons in M shell.
i. Identify the element X and write the number of protons and electrons in it. [3]
ii. Size of X-ion is greater than that of X atom though both contain the same number of protons. Give reason. [1]
iii. Write down the formula of one of the compounds of X where X is in −3 oxidation state. [1]
Know how ionization energy (IE) of element is crucial aspect in the study of chemical bonding whether they form ionic or covalent bond. The first ionization energies of period second elements are given below:
Name of elements | Li | Be | B | C | N | O | F | Ne |
|---|---|---|---|---|---|---|---|---|
First ionization energy (kJ/mol) | 520 | 899 | 801 | 1086 | 1403 | 1410 | 1681 | 2080 |
i. Define first ionization energy. [1]
ii. Name a factor that affects the value of IE. [1]
iii. Which of the element is most difficult to ionize? [1]
iv. Why is there steep rise in IE from carbon to nitrogen?[2]
When electricity is passed through the molten NaCl in the presence of CaCl₂ in the ratio 2:3 by weight using graphite anode and iron cathode as electrodes, sodium metal is deposited at cathode and chlorine gas is liberated at anode in the electrolytic cell.
i. Define electrolytic cell. [1]
ii. Find the mass of sodium deposited at cathode when 0.1 ampere of current is passed for half an hour and the process has 75% efficiency. [2]
iii. Why does calcium metal not deposit instead of sodium at the cathode? [1]
iv. Aqueous solution of sodium chloride cannot be used instead of molten sodium chloride for the same intended product. Give reason. [1]
Derive the relationship between Kp and Kc. Give one example of chemical reaction where Kp is greater than Kc. [4+1]
Derive the ideal gas equation , where the symbols have their usual meaning. State two conditions under which the behaviour of a real gas approaches that of an ideal gas. [3+2]
Concentrated sulphuric acid can be used in the laboratory to produce hydrogen chloride gas by the reaction with solid sodium chloride.
i. Hydrogen iodide is not produced by the same method as for hydrogen chloride, why? [1]
ii. What is the difference between hydrogen chloride gas and hydrochloric acid? [2]
iii. How could you identify the bottle containing HCl using ammonia gas? [2]
Depending upon the nature of minerals present in the ores, calcinations and roasting are mainly used for the conversion of ores into their respective oxides.
i. What do you mean by roasting and calcinations in the metallurgical process? [2]
ii. Name the vessel in which roasting is carried out. [1]
iii. Write the name of two possible impurities that are removed in roasting. [2]
One of the examples of homologous series is given below:
Members | Molecular formula |
|---|---|
First | CH₃OH |
Second | CH₃CH₂OH |
Third | X |
Fourth | CH₃CH₂CH₂CH₂OH |
i. Define homologous series. [1]
ii. Find the mass difference between successive members of above homologous series and calculate the molecular mass of X. [2]
iii. What is the reason behind the highest boiling point but least solubility of the fourth member in the given series? [2]
An unsaturated hydrocarbon B upon treatment with hydrogen bromide produces compound C. Compound C reacts with sodium metal in the presence of organic ether and produces compound D of molecular formula C₆H₁₄.
i. Give the chemical equations for the conversion of compound B to compound C and compound C to compound D. [2]
ii. Write down the IUPAC name of compound C and D. [2]
iii. Give the structural formula of positional isomer of compound C. [1]
Urea is a very much demanded chemical fertilizer in agricultural country like Nepal because of the lack of domestic production. One of the raw materials for urea production is ammonia which is obtained from Haber's process.
i. Draw a flow sheet diagram for the manufacture of ammonia by Haber's Bosch process. [3]
ii. What is major challenge in establishing chemical industries in the countries like Nepal? Mention how such challenge can be strategically overcome? [2]
Group 'C'
Give long answer to the following questions.
In the presence of platinum catalyst ammonia is oxidized to nitric acid. The reaction is given below.
i. Calculate the mass of nitric oxide produced by the reaction of 2 moles of ammonia with 2 moles of oxygen. [2]
ii. What is the importance of limiting reactant in chemical calculation? [1]
iii. If 2 moles of ammonia produce 50 grams of water upon reaction with excess of ammonia. What is the percentage yield of the reaction? [2]
iv. Calculate the volume of HCl gas required at 20°C and 750 mm Hg pressure which can completely react with 2 mole of ammonia gas to produce ammonium chloride. [3]
Oxygen is the third most abundant element by mass which readily forms oxides with other elements. Some of the oxides are given below.
Na₂O | Al₂O₃ | CO | SO₂ | Fe₂O₃ | H₂O₂ |
|---|
i. Identify the acidic oxide, basic oxide, neutral oxide and mixed oxide from the above table. [4]
ii. Write two chemical equations to prove that the particular oxide is amphoteric in nature. [2]
iii. Why is CO is harmful gas? [1]
iv. Write any one industrial application of oxygen gas. [1]
Sulphuric acid is one of the largest volumes of industrial chemical product in the world. Over the last decades the contact process has been used to produce sulphuric acid, replacing the traditional (Lead Chamber) process.
i. Write the four steps of chemical equation for the manufacture of sulphuric acid by Contact process starting from iron sulphide. [4]
ii. Give any two chemical equations in which sulphuric acid acts as precipitant and dehydrating agent. [2]
iii. Write the chemical equation producing fertilizer using H₂SO₄. [1]
iv. Why does H₂SO₄ always act as an oxidizing agent? [1]
An alkene X undergoes ozonolysis and gives two compounds Y and Z of molecular formula C₃H₆O. Y and Z are functional isomers of each other.
i. Write the two steps chemical equation for the conversion of X into Y and Z. [2]
ii. Write the structural formula of Y and Z. Why are they called functional isomers? [3]
iii. What happens when hydrogen gas in the presence of nickel catalyst is passed over X? [1]
iv. What is the application of ozonolysis in the organic reaction mechanism? [1]
v. How can you prove chemically the compound X is unsaturated? [1]
Paper Overview & Analysis
CDC
Year
Model Question
Type
75
Full Marks
32
Pass Marks
3 Hours
Duration
22
Question Items
Question Type Breakdown
Group Breakdown