Q.1: Answer all the following Multiple Choice Questions:
- The pressure of vapours maintained in the ionization chamber of a mass spectrometer during isotopic analysis is:
(a) High
(b) Low
(c) Moderate
(d) Zero - Volume occupied by one mole of gas at standard temperature and pressure is:
(a) 22.414 dm³
(b) 22.4 L
(c) 1 L
(d) 1 dm³ - Direct conversion of solid into its vapour is called:
(a) Crystallization
(b) Sublimation
(c) Vaporization
(d) Distribution - The SI unit of pressure is:
(a) mmHg
(b) atm
(c) pound per square inch
(d) Nm² - Deviation of gas from ideal behaviour is maximum at:
(a) -10°C and 5.0 atm
(b) -10°C and 2.0 atm
(c) 100°C and 2.0 atm
(d) 0°C and 2.0 atm - Acetone and chloroform are soluble in each other due to:
(a) Intermolecular H-bonding
(b) Ion-dipole interaction
(c) Instantaneous dipole
(d) London dispersion forces - The crystals of diamond are:
(a) Ionic
(b) Covalent
(c) Molecular
(d) Metallic - Lyman series occur in:
(a) Visible region
(b) U.V. region
(c) I.R. region
(d) Micro-wave region - Orbitals having the same energy are called:
(a) Hybrid orbitals
(b) Valence orbitals
(c) Degenerate orbitals
(d) D-orbitals - Which of the following species has unpaired electrons in antibonding molecular orbitals:
(a) O₂⁻
(b) N₂⁺
(c) B₂
(d) F₂ - One of the following molecules is polar in nature:
(a) CH₄
(b) CO₂
(c) SO₂
(d) CCl₄ - One calorie is equivalent to:
(a) 0.4184 J
(b) 41.84 J
(c) 4.184 J
(d) 418.4 J - The pH of a solution is 9, the solution is:
(a) Weakly acidic
(b) Weakly basic
(c) Strongly acidic
(d) Strongly basic - Molarity of pure water is:
(a) 1
(b) 18
(c) 55.5
(d) 6 - The salt that when dissolved in water forms a solution with pH greater than 7 is:
(a) CuSO₄
(b) NaCl
(c) NH₄Cl
(d) Na₂CO₃ - If the salt bridge is not used between two half-cells, then the voltage:
(a) Decreases rapidly
(b) Decreases slowly
(c) Does not change
(d) Drops to zero - In a zero-order reaction, the rate is independent of:
(a) Temperature of reaction
(b) Concentration of reactants
(c) Concentration of products
(d) Pressure
D.G. KHAN BOARD
Inter Part-I (Class 11th)
Session (2019)
Time: 2:40 Hours
Subjective
Marks: 68
Note:
- Section I is compulsory.
- Attempt any 3 questions from Section II.
Section I
Q.2: Write short answers to any Eight parts.
- What are monoisotopic elements? Give the name and symbol of such an element.
- What is a molecular ion? Write formulas of any two of these ions.
- Define Avogadro’s number. Give its numerical value.
- Write down four steps for the complete quantitative determination of a sample.
- State the distribution law.
- What is the critical temperature of a gas? Write the name and formula of a gas whose critical temperature is above room temperature.
- Describe two causes of deviation of a real gas from ideal behaviour.
- What is absolute zero? Show it by drawing a graph between volume and temperature.
- State Graham’s law of effusion. Give its equation.
- What is upper consulate temperature? Give names of two liquids that are partially miscible with each other.
- What is meant by a hydrate? Give formulas of any two hydrates.
- Why is the heat of hydration of Li⁺ greater than that of Cs⁺?
Section II
Q.3: Write short answers to any Eight parts.
- Boiling points of halogens increase going down the group. Give the reason.
- Earthenware vessels keep the water cool. Explain.
- Why do ionic solids not conduct electricity in the solid state?
- Define the order of reaction and specific rate constant.
- Define transition temperature. Give one example.
- Write down any two properties of a neutron.
- Explain atomic spectrum with one example.
- Mention any two defects in Rutherford’s atomic model.
- Define the (n+1) rule.
- Discuss the effect of a common ion on the solubility of sparingly soluble salts with one example.
- How is the direction of reaction predicted by knowing its Kc value?
- Explain the effect of surface area on the rate of a chemical reaction with one example.
Q.4: Write short answers to any Six parts.
- Differentiate between bonding molecular orbital and anti-bonding molecular orbital.
- Why is a polar bond stronger than a non-polar bond?
- Why is the abnormality of bond length and bond strength in HI less prominent than in HCl?
- Why can’t atomic radii be measured precisely?
- Justify that the heat of formation of a compound is the sum of all other enthalpies.
- Describe Standard Enthalpy of solution with an example.
- How is impure copper (Cu) purified by electrolysis?
- How can the feasibility of a reaction be predicted from the electrochemical series?
- Write the reactions involved in an alkaline battery.
Section III
Note: Attempt any three (3) questions.
Q.5:
(a) Define stoichiometry. Give its assumptions. Mention two important laws that help in performing stoichiometric calculations.
(b) Explain H-bonding. Discuss any three applications of H-bonding.
Q.6:
(a) Calculate the density of CH₄ at 0°C and one atmospheric pressure.
(b) Write down the postulates of Bohr’s atomic model.
Q.7:
(a) Draw the shape of O₂ molecules according to molecular orbital theory.
(b) Define spontaneous and non-spontaneous processes. Give two examples of each.
Q.8:
(a) The solubility of PbF₂ at 25°C is 0.64 g/dm³. Calculate the Ksp of PbF₂. (Molar mass of PbF₂ = 245.2 g/mol)
(b) Define enzyme. Mention three characteristics of enzyme catalysis.
Q.9:
(a) State Raoult’s Law in three different ways.
(b) Describe the construction and working of a Galvanic cell.